Include malloc.h if available, also when compiling with gcc.

ChangeLog

 2012-07-03  Niels Möller  <nisse@lysator.liu.se>
 
+	* aclocal.m4 (LSH_FUNC_ALLOCA): In the config.h boilerplate,
+	include malloc.h if it exists, also when compiling with gcc.
+	Needed for cross-compiling with --host=i586-mingw32msvc.
+
 	* examples/base16dec.c: Don't #include files using <nettle/...>,
 	we don't want to pick up installed versions.
 	* examples/base16enc.c: Likewise.

aclocal.m4

@@ -369,6 +369,11 @@ char *alloca ();
 #else /* defined __GNUC__ */
 # if HAVE_ALLOCA_H
 #  include <alloca.h>
+# else
+/* Needed for alloca on windows, also with gcc */
+#  if HAVE_MALLOC_H
+#   include <malloc.h>
+#  endif
 # endif
 #endif
 ])])