bump internal libast version; various minor cleanups

These are minor things I accumulated over the last month or so.

Notable changes:

src/lib/libast/features/api,
src/lib/libast/misc/state.c,
src/lib/libast/comp/conf.tab,
src/cmd/ksh93/include/defs.h:
- Bump internal libast version to 20220101L. We've made a few
  additions to the API, at least pathicase (see 71934570, ca3ec200)
  and astconf_long (see c2ac69b2), so this should have been done
  already. This also updates '/opt/ast/bin/getconf _AST_VERSION'.
- Use AST_VERSION instead of outdated _AST_VERSION.
- In state.c, use AST_VERSION instead of hardcoding the version.

src/cmd/ksh93/sh/xec.c:
- Remove 'restorefd' variable, unused as of 42becab6.
- Remove 'cmdrecurse' function and SH_RUNPROG macro; this was once
  used by a few libcmd commands, but ast-open-archive reveals it's
  unused as of ast 1999-12-25.

src/cmd/ksh93/sh/*.c:
- Where available, use e_dot instead of "." for consistency; it is
  defined as an extern so we might as well use it.

src/cmd/ksh93/tests/*.sh:
- When reporting signal names in fails, include the SIG prefix.
- Fix a broken process hang test in subshell.sh.

src/lib/libast/man/sfdisc.3:
- Removed. The interfaces described here never made it out of AT&T;
  they do not exist in any libast version in ast-open-archive.
  Resolves: https://github.com/ksh93/ksh/issues/426

src/cmd/ksh93/tests/basic.sh

@@ -693,7 +693,7 @@ got=$(set +x; { "$SHELL" -c '
 	echo baz				# 7
 '; } 2>&1)
 ((!(e = $?))) && [[ $got == "$exp" ]] || err_exit 'Redirection in DEBUG trap corrupts the trap' \
-	"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+	"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 
 # The DEBUG trap crashed when re-trapping inside a subshell
 exp=$'trap -- \': main\' EXIT\ntrap -- \': main\' ERR\ntrap -- \': main\' KEYBD\ntrap -- \': main\' DEBUG'
@@ -707,7 +707,7 @@ got=$(set +x; { "$SHELL" -c '
 	done
 '; } 2>&1)
 ((!(e = $?))) && [[ $got == "$exp" ]] || err_exit 'Pseudosignal trap failed when re-trapping in subshell' \
-	"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+	"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 
 # Field splitting broke upon evaluating an unquoted expansion in a DEBUG trap
 exp=$'a\nb\nc'
@@ -720,7 +720,7 @@ got=$(set +x; { "$SHELL" -c '
 	printf "%s\n" "$@"
 '; } 2>&1)
 ((!(e = $?))) && [[ $got == "$exp" ]] || err_exit 'Field splitting broke after executing DEBUG trap' \
-	"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+	"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 
 # The DEBUG trap had side effects on the exit status
 trap ':' DEBUG

src/cmd/ksh93/tests/builtins.sh

@@ -1162,7 +1162,7 @@ then	got=$( { "$SHELL" -c '
 		done
 	'; } 2>&1)
 	((!(e = $?))) || err_exit 'crash with alarm and IFS' \
-		"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+		"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 fi
 
 # ======

src/cmd/ksh93/tests/functions.sh

@@ -1340,7 +1340,7 @@ cat >$tmp/crash_rhbz1117404.ksh <<-'EOF'
 EOF
 got=$( { "$SHELL" "$tmp/crash_rhbz1117404.ksh"; } 2>&1)
 ((!(e = $?))) || err_exit 'crash while handling function-local trap' \
-	"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+	"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 
 # ======
 exit $((Errors<125?Errors:125))

src/cmd/ksh93/tests/io.sh

@@ -714,7 +714,7 @@ got=$(command -x cat <(command -x echo foo) 2>&1) || err_exit "process substitut
 	exit
 ' empty_redir_crash_test "$tmp"
 ((!(e = $?))) || err_exit 'crash on null-command redirection with DEBUG trap' \
-	"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+	"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 
 # ======
 # stdout was misdirected if an EXIT/ERR trap handler was defined in a -c script

src/cmd/ksh93/tests/path.sh

@@ -477,7 +477,7 @@ e=$?
 trap - TERM INT
 [[ $sleep_pid ]] && kill $sleep_pid
 ((!e)) && [[ $(<$ofile) == ok ]] || err_exit "PATH containing .paths directory:" \
-	"got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$(<$ofile)")"
+	"got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$(<$ofile)")"
 
 # ======
 # Check that 'command -p' and 'command -p -v' do not use the hash table (a.k.a. tracked aliases).
@@ -560,7 +560,7 @@ trap - TERM INT
 if	[[ ${ kill -l "$e"; } == KILL ]]
 then	warning "'command -x' test killed, probably due to lack of memory; skipping test"
 else	if	let "e > 0"
-	then	err_exit "'command -x' test yielded exit status $e$( let "e>128" && print -n / && kill -l "$e")"
+	then	err_exit "'command -x' test yielded exit status $e$( let "e>128" && print -n /SIG && kill -l "$e")"
 	fi
 	if	[[ ! -s $ofile ]]
 	then	err_exit "'command -x' test failed to produce output"
@@ -698,7 +698,7 @@ e=$?
 trap - TERM INT
 [[ $sleep_pid ]] && kill $sleep_pid
 ((e == 127)) || err_exit "Long nonexistent command name:" \
-	"got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$(<$ofile)")"
+	"got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$(<$ofile)")"
 
 # ======
 # A function autoload recursion loop used to crash
@@ -716,7 +716,7 @@ $SHELL: function, built-in or type definition for self2 not found in $tmp/fun.$$
 $SHELL: function, built-in or type definition for self not found in $tmp/fun.$$/self"
 got=$({ FPATH=$tmp/fun.$$ "$SHELL" -c self; } 2>&1)
 (((e = $?) == 126)) || err_exit 'Function autoload recursion loop:' \
-	"got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got")"
+	"got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got")"
 
 # ======
 # If a shared-state ${ command substitution; } changed the value of $PATH, the variable

src/cmd/ksh93/tests/signal.sh

@@ -496,7 +496,7 @@ got=$(export sig; "$SHELL" -c '
 	trap - "$sig"
 ' 2>&1)
 ((!(e = $?))) && [[ $got == "$exp" ]] || err_exit "failed to handle SIG$sig from subshell" \
-	"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+	"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 
 got=$(export sig; "$SHELL" -c '
 	function tryTrap
@@ -508,7 +508,7 @@ got=$(export sig; "$SHELL" -c '
 	trap - "$sig"
 ' 2>&1)
 ((!(e = $?))) && [[ $got == "$exp" ]] || err_exit "failed to handle SIG$sig from ksh function" \
-	"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+	"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 
 # ======
 # ksh-style functions didn't handle signals other than SIGINT and SIGQUIT (rhbz#1454804)
@@ -526,7 +526,7 @@ got=$(export exp; "$SHELL" -c '
 ' 2>&1)
 got=${got% }	# rm final space
 ((!(e = $?))) && [[ $got == "$exp" ]] || err_exit "ksh function ignores global signal traps" \
-	"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+	"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 
 # ======
 # Signal incorrectly issued when function returns with status > 256 and EXIT trap is active

src/cmd/ksh93/tests/subshell.sh

@@ -551,11 +551,16 @@ $SHELL <<- \EOF
 		print -u2 done
 	}
 	out=$(eval "foo | cat" 2>&1)
-	(( ${#out} == 96011 )) || err_exit "\${#out} is ${#out} should be 96011"
+	print "${#out}" >out
 EOF
 } & pid=$!
-$SHELL -c "{ sleep .4 && kill $pid ;}" 2> /dev/null
-(( $? == 0 )) &&  err_exit 'process has hung'
+(sleep 4; kill -s KILL "$pid" 2>/dev/null) &	# another bg job to kill frozen test job
+{ wait "$pid"; } 2>/dev/null			# get job's exit status, suppressing signal messages
+if	((!(e = $?)))
+then	[[ $(<out) == '96011' ]] || err_exit "\${#out} is $(printf %q "$(<out)"), should be 96011"
+else	err_exit "process has hung (got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"))"
+fi
+kill "$!" 2>/dev/null				# kill sleep process
 
 {
 x=$( $SHELL  <<- \EOF
@@ -848,7 +853,7 @@ test_pid=$!
 (sleep 10; kill -s KILL "$test_pid" 2>/dev/null) &	# another bg job to kill frozen test job
 sleep_pid=$!
 { wait "$test_pid"; } 2>/dev/null			# get job's exit status, suppressing signal messages
-((!(e = $?))) || err_exit "backtick comsub crash/freeze (got status $e$( ((e>128)) && print -n / && kill -l "$e"))"
+((!(e = $?))) || err_exit "backtick comsub crash/freeze (got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"))"
 kill "$sleep_pid" 2>/dev/null
 
 # ======
@@ -858,7 +863,7 @@ test_pid=$!
 (sleep 2; kill -s KILL "$test_pid" 2>/dev/null) &
 sleep_pid=$!
 { wait "$test_pid"; } 2>/dev/null
-((!(e = $?))) || err_exit "backtick comsub hang (got status $e$( ((e>128)) && print -n / && kill -l "$e"))"
+((!(e = $?))) || err_exit "backtick comsub hang (got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"))"
 kill "$sleep_pid" 2>/dev/null
 
 # Backtick command substitution with pipe hangs when filling out pipe buffer (rhbz#1138751)
@@ -867,7 +872,7 @@ test_pid=$!
 (sleep 2; kill -s KILL "$test_pid" 2>/dev/null) &
 sleep_pid=$!
 { wait "$test_pid"; } 2>/dev/null
-((!(e = $?))) || err_exit "backtick comsub with pipe hangs (got status $e$( ((e>128)) && print -n / && kill -l "$e"))"
+((!(e = $?))) || err_exit "backtick comsub with pipe hangs (got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"))"
 kill "$sleep_pid" 2>/dev/null
 
 # ======
@@ -924,7 +929,7 @@ cat >$tmp/crash_rhbz1117404.ksh <<-'EOF'
 EOF
 got=$( { "$SHELL" "$tmp/crash_rhbz1117404.ksh"; } 2>&1)
 ((!(e = $?))) || err_exit 'crash while handling subshell trap' \
-	"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+	"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 
 # ======
 # Segmentation fault when using cd in a subshell, when current directory cannot be determined
@@ -941,14 +946,14 @@ got=$(set +x; { "$SHELL" -c '(subshfn() { bad; }; cd ..; echo "subPWD: $PWD"); t
 exp="PWD=$PWD"
 got=$(set +x; { "$SHELL" -c '(cd /; (cd /)); print -r -- "PWD=$PWD"'; } 2>&1)
 ((!(e = $?))) && [[ $got == "$exp" ]] || err_exit 'failed to restore nonexistent PWD on exiting a virtual subshell' \
-	"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+	"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 mkdir "$tmp/recreated"
 cd "$tmp/recreated"
 tmp=$tmp "$SHELL" -c 'cd /; rmdir "$tmp/recreated"; mkdir "$tmp/recreated"'
 exp="PWD=$PWD"
 got=$(set +x; { "$SHELL" -c '(cd /); print -r -- "PWD=$PWD"'; } 2>&1)
 ((!(e = $?))) && [[ $got == "$exp" ]] || err_exit 'failed to restore re-created PWD on exiting a virtual subshell' \
-	"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+	"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 cd "$tmp"
 
 # ======

src/cmd/ksh93/tests/tilde.sh

@@ -113,7 +113,7 @@ HOME=$saveHOME
 if builtin .sh.tilde 2>/dev/null
 then	got=$(.sh.tilde & wait "$!" 2>&1)
 	((!(e = $?))) || err_exit ".sh.tilde builtin crashes the shell" \
-		"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
+		"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$got"))"
 fi
 
 # ... and replaced by a proper use of discipline functions that allows customising tilde expansion.
@@ -164,7 +164,7 @@ do	(
 	if	((!(e = $?)))
 	then	read Errors <$tmp/Errors
 	else	err_exit ".sh.tilde.$disc discipline function crashes the shell" \
-			"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$(<crashmsg)"))"
+			"(got status $e$( ((e>128)) && print -n /SIG && kill -l "$e"), $(printf %q "$(<crashmsg)"))"
 	fi
 done
 

src/cmd/ksh93/tests/variables.sh

@@ -1052,7 +1052,7 @@ $SHELL -c '
 	exit $((errors + 1))	# a possible erroneous asynchronous fork would cause exit status 0
 ' unset_test "$@"
 (((e = $?) == 1)) || err_exit "Failure in unsetting one or more special variables" \
-	"(exit status $e$( ((e>128)) && print -n / && kill -l "$e"))"
+	"(exit status $e$( ((e>128)) && print -n /SIG && kill -l "$e"))"
 
 # ... unset in virtual subshell inside of nested function
 $SHELL -c '
@@ -1082,7 +1082,7 @@ $SHELL -c '
 	exit $((errors + 1))	# a possible erroneous asynchronous fork would cause exit status 0
 ' unset_subsh_fun_test "$@"
 (((e = $?) == 1)) || err_exit "Unset of special variable(s) in a virtual subshell within a nested function fails" \
-	"(exit status $e$( ((e>128)) && print -n / && kill -l "$e"))"
+	"(exit status $e$( ((e>128)) && print -n /SIG && kill -l "$e"))"
 
 # ... readonly in subshell
 $SHELL -c '
@@ -1106,7 +1106,7 @@ $SHELL -c '
 	exit $((errors + 1))	# a possible erroneous asynchronous fork would cause exit status 0
 ' readonly_test "$@"
 (((e = $?) == 1)) || err_exit "Failure in making one or more special variables readonly in a subshell" \
-	"(exit status $e$( ((e>128)) && print -n / && kill -l "$e"))"
+	"(exit status $e$( ((e>128)) && print -n /SIG && kill -l "$e"))"
 
 # ... subshell leak test
 $SHELL -c '
@@ -1123,7 +1123,7 @@ $SHELL -c '
 	exit $((errors + 1))
 ' subshell_leak_test "$@"
 (((e = $?) == 1)) || err_exit "One or more special variables leak out of a subshell" \
-	"(exit status $e$( ((e>128)) && print -n / && kill -l "$e"))"
+	"(exit status $e$( ((e>128)) && print -n /SIG && kill -l "$e"))"
 
 # ... upper/lowercase test
 $SHELL -c '
@@ -1159,7 +1159,7 @@ $SHELL -c '
 	exit $((errors + 1))
 ' changecase_test "$@"
 (((e = $?) == 1)) || err_exit "typeset -l/-u doesn't work on special variables" \
-	"(exit status $e$( ((e>128)) && print -n / && kill -l "$e"))"
+	"(exit status $e$( ((e>128)) && print -n /SIG && kill -l "$e"))"
 
 # ... unset followed by launching a forked subshell
 $SHELL -c '
@@ -1176,7 +1176,7 @@ $SHELL -c '
 	exit $?
 ' unset_to_fork_test "$@"
 (((e = $?) == 1)) || err_exit "Failure in unsetting one or more special variables followed by launching forked subshell" \
-	"(exit status $e$( ((e>128)) && print -n / && kill -l "$e"))"
+	"(exit status $e$( ((e>128)) && print -n /SIG && kill -l "$e"))"
 
 # ======
 # ${.sh.pid} should be the forked subshell's PID