Use HAVE_CONFIG_H to include <stdlib.h> and <string.h> in getopt sources.

external/gpl2/mkhybrid/bin/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.2 2024/05/31 20:27:19 tsutsui Exp $
+#	$NetBSD: Makefile,v 1.3 2024/05/31 20:41:50 tsutsui Exp $
 #	$OpenBSD: Makefile,v 1.8 2022/07/11 03:11:49 daniel Exp $
 
 # NOTE: The mkhybrid distrib also makes an "mkisofs" which is the same binary
@@ -25,6 +25,7 @@ SRCS+=	block.c btree.c data.c file.c hfs.c low.c lvolume.c node.c record.c
 SRCS+=	apprentice.c lfile.c softmagic.c
 
 CPPFLAGS+=-DSYSTEM_ID_DEFAULT=\"NetBSD\" -DAPPLE_HYB -DVANILLA_AUTOCONF \
+	-DHAVE_CONFIG_H \
 	-I${DIST} -I${DIST}/include \
 	-I${DIST}/libhfs_iso \
 	-I${DIST}/libfile

external/gpl2/mkhybrid/dist/getopt.c

@@ -70,7 +70,7 @@ the executable file might be covered by the GNU General Public License. */
 
 /* This needs to come after some library #include
    to get __GNU_LIBRARY__ defined.  */
-#if defined(__GNU_LIBRARY__) || defined(__OpenBSD__)
+#if defined(HAVE_STDLIB_H)
 /* Don't include stdlib.h for non-GNU C libraries because some of them
    contain conflicting prototypes for getopt.  */
 #include <stdlib.h>
@@ -169,7 +169,7 @@ static enum
   REQUIRE_ORDER, PERMUTE, RETURN_IN_ORDER
 } ordering;
 
-#if defined(__GNU_LIBRARY__) || defined(__OpenBSD__)
+#if defined(HAVE_STRING_H)
 /* We want to avoid inclusion of string.h with non-GNU libraries
    because there are many ways it can cause trouble.
    On some systems, it contains special magic macros that don't work

external/gpl2/mkhybrid/dist/getopt1.c

@@ -55,7 +55,7 @@
 
 /* This needs to come after some library #include
    to get __GNU_LIBRARY__ defined.  */
-#ifdef __GNU_LIBRARY__
+#if defined(HAVE_STDLIB_H)
 #include <stdlib.h>
 #else
 char *getenv ();