Native try-catch syntax parsing should not crash.

R=littledan@chromium.org
BUG=chromium:630559

Review-Url: https://codereview.chromium.org/2176613002
Cr-Commit-Position: refs/heads/master@{#37996}

src/parsing/parser.cc

@@ -2993,19 +2993,19 @@ TryStatement* Parser::ParseTryStatement(bool* ok) {
   }
 
   Token::Value tok = peek();
+
   bool catch_for_promise_reject = false;
-  if (tok != Token::CATCH && tok != Token::FINALLY) {
   if (allow_natives() && tok == Token::MOD) {
     Consume(Token::MOD);
     catch_for_promise_reject = true;
     tok = peek();
-      DCHECK_EQ(Token::CATCH, tok);
-    } else {
+  }
+
+  if (tok != Token::CATCH && tok != Token::FINALLY) {
     ReportMessage(MessageTemplate::kNoCatchOrFinally);
     *ok = false;
     return NULL;
   }
-  }
 
   Scope* catch_scope = NULL;
   Variable* catch_variable = NULL;

test/mjsunit/regress/regress-crbug-630559.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+assertThrows("try{}%");