typeset: add error msgs for incompatible options; improve usage msg

This adds informative error messages if incompatible options are
given. It also documents the exclusive -m, -n and -T options on
separate usage lines, as was already done with -f. The usage
message for incompatible options now looks something like this:

| $ ksh -c 'typeset -L10 -F -f -i foo'
| ksh: typeset: -i/-F/-E/-X cannot be used with -L/-R/-Z
| ksh: typeset: -f cannot be used with other options
| Usage: typeset [-bflmnprstuxACHS] [-a[type]] [-i[base]] [-E[n]]
|                [-F[n]] [-L[n]] [-M[mapping]] [-R[n]] [-X[n]]
|                [-h string] [-T[tname]] [-Z[n]] [name[=value]...]
|    Or: typeset -f [name...]
|    Or: typeset -m [name=name...]
|    Or: typeset -n [name=name...]
|    Or: typeset -T [tname[=(type definition)]...]
|  Help: typeset [ --help | --man ] 2>&1

(see also the previous commit, e21a053e)

Unfortunately the first "Usage" line has some redundancies with the
"Or:" lines showing separate usages. It doesn't seem to be possible
to avoid this; it's a flaw in how libast generates everything
(usage, help, manual) from one huge getopt(3) string. I still think
the three added "Or:" lines are an improvement as it wasn't
previously shown that these options need to be used on their own.

src/cmd/ksh93/bltins/typeset.c: b_typeset():
- Instead of only showing a generic usage message, add an
  informative error message if incompatible options were given.
- Conflicting options detection was failing because NV_LJUST and
  NV_EXPNOTE have the same bitmask value. Use a new 'isadjust'
  flag for -L/-R/-Z to remember if one of these was set.
- Detect conflict between -L/-R/-Z and a float option, not just -i.

src/cmd/ksh93/include/name.h, src/cmd/ksh93/data/msg.c:
- Add the two new error messages for incompatible options.

src/cmd/ksh93/data/builtins.c: sh_opttypeset[]:
- Add a space after 'float' in in "[+float?\btypeset -lE\b]" as
  this makes 'float' appear on its own line, improving formatting.
- Show -m, -n, -T on separate usage lines like -f, as none of these
  can be combined with other options.
- Remove "cannot be combined with other options" from -m and -n
  descriptions, as that should now be clear from the separate usage
  lines -- and even if not, the error message is now informative.

src/cmd/ksh93/sh.1, src/cmd/ksh93/COMPATIBILITY:
- Update.

src/cmd/ksh93/tests/types.sh:
- Remove obsolete test: 'typeset -RF' is no longer accepted.
  (It crashed in 93u+, so this is not an incompatibility...)

Resolves: https://github.com/ksh93/ksh/issues/48

src/cmd/ksh93/data/builtins.c

@@ -1718,7 +1718,7 @@ USAGE_LICENSE
 ;
 
 const char sh_opttypeset[] =
-"+[-1c?\n@(#)$Id: typeset (AT&T Research/ksh93) 2020-07-15 $\n]"
+"+[-1c?\n@(#)$Id: typeset (AT&T Research/ksh93) 2021-01-20 $\n]"
 USAGE_LICENSE
 "[+NAME?typeset - declare or display variables with attributes]"
 "[+DESCRIPTION?Without the \b-f\b option, \btypeset\b sets, unsets, "
@@ -1738,7 +1738,7 @@ USAGE_LICENSE
 "[+?Note also the following builtin command equivalents:]{"
 	"[+autoload?\btypeset -fu\b]"
 	"[+compound?\btypeset -C\b]"
-	"[+float?\btypeset -lE\b]"
+	"[+float ?\btypeset -lE\b]"
 	"[+functions?\btypeset -f\b]"
 	"[+integer?\btypeset -li\b]"
 	"[+nameref?\btypeset -n\b]"
@@ -1768,11 +1768,9 @@ USAGE_LICENSE
 "[l?Without \b-i\b, sets character mapping to \btolower\b. When used "
 	"with \b-i\b, \b-E\b, or \b-F\b indicates long variant.]"
 "[m?Move.  The value is the name of a variable whose value will be "
-	"moved to \aname\a.  The original variable will be unset.  Cannot be "
-	"used with any other options.]"
+	"moved to \aname\a.  The original variable will be unset.]"
 "[n?Name reference.  The value is the name of a variable that \aname\a "
-	"references.  \aname\a cannot contain a \b.\b.  Cannot be used with "
-	"any other options.]"
+	"references.  \aname\a cannot contain a \b.\b.]"
 "[p?Causes the output to be in a format that can be used as input to the "
 	"shell to recreate the attributes for variables.]"
 "[r?Enables readonly.  Once enabled it cannot be disabled.  See "
@@ -1830,6 +1828,9 @@ USAGE_LICENSE
 "\n"
 "\n[name[=value]...]\n"
 " -f [name...]\n"
+" -m [name=name...]\n"
+" -n [name=name...]\n"
+" -T [tname[=(type definition)]...]\n"
 "\n"
 "[+EXIT STATUS?]{"
         "[+0?No errors occurred.]"