build: ksh93: some iffe and SHOPT.sh streamlining

In ksh93/Mamfile there are four iffe invocations that don't run
a script but run one 'def' command directly from the iffe command
line. The 'def' command causes 8 probes to be run (per iffe --man):

    def name
          Equivalent to cmd,dat,hdr,key,lib,mth,sys,typ name.

This was quite inefficient as only one or two of them were used.

The process is streamlined by eliminating the individual iffe
invocations and adding only the probes whose results are actually
used to FEATURE/options (the test for sys/acct.h) and
FEATURE/externs (the rest).

The execargs.h probe and the code depending on it (in main.c) are
removed as this is only relevant for the PDP-11 (RIP, 1970-1997).

This commit also has a bugfix for SHOPT.sh processing in
ksh93/Mamfile. It was not effective to set SHOPT_GLOBCASEDET to 0
on systems where case-insensitive file systems are detected (e.g.
macOS). The fix is to include FEATURE/options in shopt.h after, not
before, the SHOPT.sh-based defines.

src/cmd/ksh93/Mamfile

@@ -86,10 +86,10 @@ make install
 			exec -	exec >shopt.h
 			exec -	echo '/* Generated from ksh93/SHOPT.sh by ksh93/Mamfile */'
 			exec -	echo
-			exec -	echo '#include "FEATURE/options"'
-			exec -	echo
 			exec -	. "$PACKAGEROOT/src/cmd/ksh93/SHOPT.sh"
 			exec -	${STDCAT} <<-EOF
+			exec -		#include "FEATURE/options"
+			exec -
 			exec -		/* overrides */
 			exec -		#if SHOPT_SCRIPTONLY
 			exec -		#   undef SHOPT_ACCT
@@ -99,6 +99,9 @@ make install
 			exec -		#   undef SHOPT_SYSRC
 			exec -		#   undef SHOPT_VSH
 			exec -		#endif
+			exec -		#if !_sys_acct
+			exec -		#   undef SHOPT_ACCT
+			exec -		#endif
 			exec -	EOF
 		done shopt.h generated
 		make pmain.o
@@ -269,10 +272,6 @@ make install
 					prev include/builtins.h
 					prev include/name.h
 					make include/path.h implicit
-						make FEATURE/acct implicit
-							prev Mamfile
-							exec - iffe ${IFFEFLAGS} -v -c "${CC} ${mam_cc_FLAGS} ${CCFLAGS} ${LDFLAGS}" ref ${mam_cc_L+-L.} ${mam_cc_L+-L${INSTALLROOT}/lib} -I${PACKAGE_ast_INCLUDE} -I${INSTALLROOT}/include ${mam_libdll} ${mam_libcmd} ${mam_libast} ${mam_libm} ${mam_libnsl} : def acct
-						done FEATURE/acct generated
 						prev include/defs.h
 						prev include/nval.h
 					done include/path.h
@@ -559,21 +558,8 @@ make install
 			done whence.o generated
 			make main.o
 				make sh/main.c
-					prev execargs.h implicit dontcare virtual
 					prev nc.h implicit dontcare virtual
 					prev FEATURE/externs
-					make FEATURE/execargs implicit
-						prev Mamfile
-						exec - iffe ${IFFEFLAGS} -v -c "${CC} ${mam_cc_FLAGS} ${CCFLAGS} ${LDFLAGS}" ref ${mam_cc_L+-L.} ${mam_cc_L+-L${INSTALLROOT}/lib} -I${PACKAGE_ast_INCLUDE} -I${INSTALLROOT}/include ${mam_libdll} ${mam_libcmd} ${mam_libast} ${mam_libm} ${mam_libnsl} : def execargs
-					done FEATURE/execargs generated
-					make FEATURE/pstat implicit
-						prev Mamfile
-						exec - iffe ${IFFEFLAGS} -v -c "${CC} ${mam_cc_FLAGS} ${CCFLAGS} ${LDFLAGS}" ref ${mam_cc_L+-L.} ${mam_cc_L+-L${INSTALLROOT}/lib} -I${PACKAGE_ast_INCLUDE} -I${INSTALLROOT}/include ${mam_libdll} ${mam_libcmd} ${mam_libast} ${mam_libm} ${mam_libnsl} : def pstat
-					done FEATURE/pstat generated
-					make FEATURE/setproctitle implicit
-						prev Mamfile
-						exec - iffe ${IFFEFLAGS} -v -c "${CC} ${mam_cc_FLAGS} ${CCFLAGS} ${LDFLAGS}" ref ${mam_cc_L+-L.} ${mam_cc_L+-L${INSTALLROOT}/lib} -I${PACKAGE_ast_INCLUDE} -I${INSTALLROOT}/include ${mam_libdll} ${mam_libcmd} ${mam_libast} ${mam_libm} ${mam_libnsl} : def setproctitle
-					done FEATURE/setproctitle generated
 					prev FEATURE/time
 					prev include/timeout.h implicit
 					prev include/history.h

src/cmd/ksh93/features/externs

@@ -1,9 +1,12 @@
-hdr	nc,exec_attr
+hdr	nc
 mem	exception.name,_exception.name math.h
-lib	setreuid,setregid,nice,fork,spawnveg,fchdir
-lib	pathnative,pathposix,fts_notify
+lib	setreuid,setregid,nice,fork,fchdir
+lib	pathnative,pathposix
 lib	memcntl sys/mman.h
-lib	getexecuser,free_execattr exec_attr.h -lsecdb
+
+# for main.c fixargs():
+lib,sys	pstat
+lib	setproctitle
 
 reference	unistd.h
 

src/cmd/ksh93/features/options

@@ -15,3 +15,6 @@ tst	note{ can we probe file system case insensitivity }end output{
 		return !r;
 	}
 }end
+
+# for SHOPT_ACCT:
+sys	acct

src/cmd/ksh93/include/path.h

@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1982-2012 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -118,15 +118,10 @@ extern const char is_ufunction[];
 extern const char e_autoloadfrom[];
 
 #if SHOPT_ACCT
-#   include	"FEATURE/acct"
-#   ifdef	_sys_acct
 	extern void sh_accinit(void);
 	extern void sh_accbegin(const char*);
 	extern void sh_accend(void);
 	extern void sh_accsusp(void);
-#   else
-#	undef	SHOPT_ACCT
-#   endif	/* _sys_acct */
 #endif /* SHOPT_ACCT */
 
 #endif /*! PATH_OFFSET */

src/cmd/ksh93/sh/main.c

@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1982-2012 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -40,9 +40,6 @@
 #include	"history.h"
 #include	"timeout.h"
 #include	"FEATURE/time"
-#include	"FEATURE/pstat"
-#include	"FEATURE/setproctitle"
-#include	"FEATURE/execargs"
 #include	"FEATURE/externs"
 #ifdef	_hdr_nc
 #   include	<nc.h>
@@ -712,14 +709,8 @@ static void chkmail(char *files)
 	stkset(sh.stk,savstak,offset);
 }
 
-#undef EXECARGS
 #undef PSTAT
-#if defined(_hdr_execargs) && defined(pdp11)
-#   include	<execargs.h>
-#   define EXECARGS	1
-#endif
-
-#if defined(_lib_pstat) && defined(_sys_pstat)
+#if _lib_pstat && _sys_pstat
 #   include	<sys/pstat.h>
 #   define PSTAT	1
 #endif
@@ -738,11 +729,7 @@ static void chkmail(char *files)
  */
 static void fixargs(char **argv, int mode)
 {
-#   if EXECARGS
-	if(mode==0)
-		return;
-	*execargs=(char *)argv;
-#   elif PSTAT
+#   if PSTAT
 	char *cp;
 	int offset=0,size;
 	static int command_len;