The -fshort-wchar option causes wchar_t to become unsigned, in addition to being
16-bits in size.  Implement this by splitting WChar into two enums, like we have
for char.  This fixes a miscompmilation of XULRunner, PR8856.

llvm-svn: 122558
diff --git a/clang/lib/Analysis/PrintfFormatString.cpp b/clang/lib/Analysis/PrintfFormatString.cpp
index daaa072..ff688e0 100644
--- a/clang/lib/Analysis/PrintfFormatString.cpp
+++ b/clang/lib/Analysis/PrintfFormatString.cpp
@@ -394,7 +394,8 @@
     LM.setKind(LengthModifier::AsShort);
     break;
 
-  case BuiltinType::WChar:
+  case BuiltinType::WChar_S:
+  case BuiltinType::WChar_U:
   case BuiltinType::Long:
   case BuiltinType::ULong:
     LM.setKind(LengthModifier::AsLong);