Backuport of upstream r64941: stdlib.h to placate clang16

2022-11-05  Sam James  <sam@gentoo.org>

	* configure.ac (Ghostscript version): #include <stdlib.h>
	to declare exit and placate clang16.
	https://tug.org/pipermail/tlbuild/2022q4/005269.html

Index: Build/source/texk/dvisvgm/configure
===================================================================
--- Build/source/texk/dvisvgm/configure	(revision 64940)
+++ Build/source/texk/dvisvgm/configure	(revision 64941)
@@ -23415,6 +23415,7 @@
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <stdio.h>
+		#include <stdlib.h>
 		#include <ghostscript/iapi.h>
 		int main () {
 			gsapi_revision_t r;
Index: Build/source/texk/dvisvgm/configure.ac
===================================================================
--- Build/source/texk/dvisvgm/configure.ac	(revision 64940)
+++ Build/source/texk/dvisvgm/configure.ac	(revision 64941)
@@ -94,6 +94,7 @@
 	# query Ghostscript version
 	AC_MSG_CHECKING([Ghostscript version])
 	AC_RUN_IFELSE([AC_LANG_SOURCE([#include <stdio.h>
+		#include <stdlib.h>
 		#include <ghostscript/iapi.h>
 		int main () {
 			gsapi_revision_t r;
Index: Build/source/texk/kpathsea/configure
===================================================================
--- Build/source/texk/kpathsea/configure	(revision 64940)
+++ Build/source/texk/kpathsea/configure	(revision 64941)
@@ -14633,7 +14633,8 @@
 else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
-int fork() { exit(1); }
+#include <stdlib.h>
+                                                 int fork() { exit(1); }
                                                  int vfork() { exit(1); }
                                                  extern char *getcwd();
                                                  char path[100];
Index: Build/source/texk/kpathsea/configure.ac
===================================================================
--- Build/source/texk/kpathsea/configure.ac	(revision 64940)
+++ Build/source/texk/kpathsea/configure.ac	(revision 64941)
@@ -45,7 +45,8 @@
 # We only need to run this if we have getcwd.
 AC_CACHE_CHECK([whether getcwd uses fork or vfork],
                [kb_cv_func_getcwd_forks],
-               [AC_RUN_IFELSE([AC_LANG_PROGRAM([[int fork() { exit(1); }
+               [AC_RUN_IFELSE([AC_LANG_PROGRAM([[#include <stdlib.h>
+                                                 int fork() { exit(1); }
                                                  int vfork() { exit(1); }
                                                  extern char *getcwd();
                                                  char path[100];]],