fix PR7192 by defining wchar_t in a more conventional way.  The
type of L"x" can change based on command line arguments.

llvm-svn: 113127
diff --git a/clang/lib/Headers/stddef.h b/clang/lib/Headers/stddef.h
index fdd4815..84ec1a7 100644
--- a/clang/lib/Headers/stddef.h
+++ b/clang/lib/Headers/stddef.h
@@ -34,7 +34,7 @@
 #ifndef __cplusplus
 #ifndef _WCHAR_T
 #define _WCHAR_T
-typedef __typeof__(*L"") wchar_t;
+typedef __WCHAR_TYPE__ wchar_t;
 #endif
 #endif