[parser] Don't rewrite parameters if has_error()

Bug: chromium:908250
Change-Id: I414255f00bf7dcec0cf8b35e314a2b9b78a9116e
Reviewed-on: https://chromium-review.googlesource.com/c/1350117
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57813}

src/parsing/parser.cc

@@ -2803,6 +2803,7 @@ class InitializerRewriter final
 };
 
 void Parser::RewriteParameterInitializer(Expression* expr) {
+  if (has_error()) return;
   InitializerRewriter rewriter(stack_limit_, expr, this);
   rewriter.Run();
 }

test/mjsunit/regress/regress-908250.js

+// Copyright 2018 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.
+
+assertThrows("(al,al,e={}=e)=>l", SyntaxError);