Parser: Fix crash on stack overflow when lazy-parsing arrow functions

test/mjsunit/regress/regress-crbug-465671.js

 // Copyright 2015 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.
 
-"use strict";
+// Flags: --harmony-arrow-functions
+
+// This used to trigger crash because of an unhandled stack overflow.
 function f() {
-  for (let v; v; ) {
-    let x;
+  var a = [10];
+  try {
+    f();
+  } catch(e) {
+    a.map(v => v + 1);
   }
 }
-
 f();