Fix SF #639945, 64-bit bug on AIX

I can't test this on the snake farm (no aix box is working).
This change works for the submitter seems correct.
Can anybody test this on 32- and 64- bit AIX?

Python/dynload_aix.c

@@ -77,8 +77,7 @@ aix_getoldmodules(void **modlistptr)
 			-- "libpython[version].a" in case it's a shared lib).
 			*/
 			offset = (unsigned int)ldiptr->ldinfo_next;
-			ldiptr = (struct ld_info *)((unsigned int)
-						    ldiptr + offset);
+			ldiptr = (struct ld_info *)((char*)ldiptr + offset);
 			continue;
 		}
 		if ((modptr = (ModulePtr)malloc(sizeof(Module))) == NULL) {
@@ -98,7 +97,7 @@ aix_getoldmodules(void **modlistptr)
 			prevmodptr->next = modptr;
 		prevmodptr = modptr;
 		offset = (unsigned int)ldiptr->ldinfo_next;
-		ldiptr = (struct ld_info *)((unsigned int)ldiptr + offset);
+		ldiptr = (struct ld_info *)((char*)ldiptr + offset);
 	} while (offset);
 	free(ldibuf);
 	return 0;