Fix GC_MALLOC_CHECK debugging output on 64-bit hosts.

* alloc.c (emacs_blocked_malloc) [GC_MALLOC_CHECK]:
Do not assume ptrdiff_t is the same width as 'int'.

src/ChangeLog

@@ -1,5 +1,9 @@
 2012-04-22  Paul Eggert  <eggert@cs.ucla.edu>
 
+	Fix GC_MALLOC_CHECK debugging output on 64-bit hosts.
+	* alloc.c (emacs_blocked_malloc) [GC_MALLOC_CHECK]:
+	Do not assume ptrdiff_t is the same width as 'int'.
+
 	* alloc.c: Handle unusual debugging option combinations.
 	(GC_CHECK_MARKED_OBJECTS): Undef if ! GC_MARK_STACK,
 	since the two debugging options are incompatible.

src/alloc.c

@@ -1314,7 +1314,7 @@ emacs_blocked_malloc (size_t size, const void *ptr)
       {
 	fprintf (stderr, "Malloc returned %p which is already in use\n",
 		 value);
-	fprintf (stderr, "Region in use is %p...%p, %u bytes, type %d\n",
+	fprintf (stderr, "Region in use is %p...%p, %td bytes, type %d\n",
 		 m->start, m->end, (char *) m->end - (char *) m->start,
 		 m->type);
 	abort ();