Fix a crash on a top-level objc string, patch by Nico Weber


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@45370 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Parse/ParseStmt.cpp b/Parse/ParseStmt.cpp
index 0637351..80d0b9e 100644
--- a/Parse/ParseStmt.cpp
+++ b/Parse/ParseStmt.cpp
@@ -87,9 +87,9 @@
   case tok::at: // May be a @try or @throw statement
     {
       AtLoc = ConsumeToken();  // consume @
-      if (Tok.getIdentifierInfo()->getObjCKeywordID() == tok::objc_try)
+      if (Tok.isObjCAtKeyword(tok::objc_try))
         return ParseObjCTryStmt(AtLoc);
-      else if (Tok.getIdentifierInfo()->getObjCKeywordID() == tok::objc_throw)
+      else if (Tok.isObjCAtKeyword(tok::objc_throw))
         return ParseObjCThrowStmt(AtLoc);
       ExprResult Res = ParseExpressionWithLeadingAt(AtLoc);
       if (Res.isInvalid) {