Don't assume that wctype produces a nice mask on all platforms. On

glibc, for instance, it's a const char *.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@134787 91177308-0d34-0410-b5e6-96231b3b80d8

include/__config

@@ -289,4 +289,8 @@ template <unsigned> struct __static_assert_check {};
 #define _LIBCPP_STABLE_APPLE_ABI
 #endif
 
+#ifdef __APPLE__
+#define _LIBCPP_WCTYPE_IS_MASK
+#endif
+
 #endif  // _LIBCPP_CONFIG