Support decltype as a simple-type-specifier.

This makes all sorts of fun examples work with decltype.
Reviewed by Richard Smith.

llvm-svn: 148787
diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index bdebb5e..606c108 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -914,6 +914,7 @@
     }
     // Fall through
       
+  case tok::annot_decltype:
   case tok::kw_char:
   case tok::kw_wchar_t:
   case tok::kw_char16_t: