C1X: implement static asserts

llvm-svn: 129555
diff --git a/clang/lib/Parse/ParseTentative.cpp b/clang/lib/Parse/ParseTentative.cpp
index 775bc93..9522691 100644
--- a/clang/lib/Parse/ParseTentative.cpp
+++ b/clang/lib/Parse/ParseTentative.cpp
@@ -58,6 +58,7 @@
   case tok::kw_using:
     // static_assert-declaration
   case tok::kw_static_assert:
+  case tok::kw__Static_assert:
     return true;
     // simple-declaration
   default: