Merge from gnulib.

ChangeLog

@@ -1,3 +1,8 @@
+2013-01-10  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Merge from gnulib, incorporating:
+	2013-01-09 stdlib: port to Solaris 2.6
+
 2013-01-04  Glenn Morris  <rgm@gnu.org>
 
 	* info/dir: Add htmlfontify.

lib/getopt.in.h

@@ -49,7 +49,9 @@
    linkers.  */
 #if defined __GETOPT_PREFIX && !defined __need_getopt
 # if !@HAVE_GETOPT_H@
+#  define __need_system_stdlib_h
 #  include <stdlib.h>
+#  undef __need_system_stdlib_h
 #  include <stdio.h>
 #  include <unistd.h>
 # endif

lib/stdlib.in.h

@@ -20,8 +20,9 @@
 #endif
 @PRAGMA_COLUMNS@
 
-#if defined __need_malloc_and_calloc
-/* Special invocation convention inside glibc header files.  */
+#if defined __need_system_stdlib_h || defined __need_malloc_and_calloc
+/* Special invocation conventions inside some gnulib header files,
+   and inside some glibc header files, respectively.  */
 
 #@INCLUDE_NEXT@ @NEXT_STDLIB_H@
 

lib/unistd.in.h

@@ -79,7 +79,9 @@
 /* Solaris declares getcwd not only in <unistd.h> but also in <stdlib.h>.  */
 /* But avoid namespace pollution on glibc systems.  */
 #ifndef __GLIBC__
+# define __need_system_stdlib_h
 # include <stdlib.h>
+# undef __need_system_stdlib_h
 #endif
 
 /* Native Windows platforms declare chdir, getcwd, rmdir in