cleanup: remove pointless no-op 'fc' and 'type' aliases

Both 'fc' and 'type' are already implemented as perfectly
functional builtins -- in fact they use the exact same C function
as 'hist' and 'whence', so the behaviour is clearly identical.

Except 'type' was aliased to 'whence -v', but b_whence() contains
explicit code to activate the v flag if invoked as 'type', so the
alias is not needed for that either.

It looks like someone decided to implement these aliases as proper
builtins (as they should be; they are POSIX standard commands and
'unalias -a' must not get rid of them), but then forgot to remove
these default aliases (and to update the man page).

I'm not even doing a NEWS entry for this as there is no change in
behaviour. The only difference is that you now get the correct
command name in error and usage messages for 'fc' and 'type'.

src/cmd/ksh93/data/aliases.c:
- Remove fc='hist' and type='whence -v' default aliases.

src/cmd/ksh93/sh.1:
- Remove those default aliases from the list.
- Document 'fc' and 'type' builtins.

(cherry picked from commit c73af6a5a36a72c681201c9e9c397f98bbf2a86d)

src/cmd/ksh93/data/aliases.c

@@ -34,7 +34,6 @@ const struct shtable2 shtab_aliases[] =
 #endif /* SHOPT_FS_3D */
 	"autoload",	NV_NOFREE,		"typeset -fu",
 	"compound",	NV_NOFREE|BLT_DCL,	"typeset -C",
-	"fc",		NV_NOFREE,		"hist",
 	"float",	NV_NOFREE|BLT_DCL,	"typeset -lE",
 	"functions",	NV_NOFREE,		"typeset -f",
 	"hash",		NV_NOFREE,		"alias -t --",
@@ -48,7 +47,6 @@ const struct shtable2 shtab_aliases[] =
 	"stop",		NV_NOFREE,		"kill -s STOP",
 	"suspend", 	NV_NOFREE,		"kill -s STOP $$",
 #endif /*SIGTSTP */
-	"type",		NV_NOFREE,		"whence -v",
 	"",		0,			(char*)0
 };