Diagnose use of _Thread_local as an extension when not in C11 mode.

llvm-svn: 369954
diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index 43b87b9..2eb8ff9 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -1191,7 +1191,7 @@
   }
   case tok::kw__Alignof:   // unary-expression: '_Alignof' '(' type-name ')'
     if (!getLangOpts().C11)
-      Diag(Tok, diag::ext_c11_alignment) << Tok.getName();
+      Diag(Tok, diag::ext_c11_feature) << Tok.getName();
     LLVM_FALLTHROUGH;
   case tok::kw_alignof:    // unary-expression: 'alignof' '(' type-id ')'
   case tok::kw___alignof:  // unary-expression: '__alignof' unary-expression