Patch by Xing Xue to improve libc++ support for AIX

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@195144 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/src/locale.cpp b/src/locale.cpp
index a326323..8e7fdb4 100644
--- a/src/locale.cpp
+++ b/src/locale.cpp
@@ -1036,7 +1036,7 @@
 #elif defined(__EMSCRIPTEN__)
     return *__ctype_b_loc();
 #elif defined(_AIX)
-    return (const unsigned long *)__lc_ctype_ptr->obj->mask;
+    return (const unsigned int *)__lc_ctype_ptr->obj->mask;
 #else
     // Platform not supported: abort so the person doing the port knows what to
     // fix