[parser] Fix bug in destructuring binding for catch.

test/mjsunit/regress/regress-5178.js

Index: test/mjsunit/regress/regress-5178.js
diff --git a/test/mjsunit/regress/regress-4967.js b/test/mjsunit/regress/regress-5178.js
similarity index 70%
copy from test/mjsunit/regress/regress-4967.js
copy to test/mjsunit/regress/regress-5178.js
index 9b36405cf4ec5538111a681e407be75fd93a08b9..bc0dd118d09be270cd659379767856f83c921718 100644
--- a/test/mjsunit/regress/regress-4967.js
+++ b/test/mjsunit/regress/regress-5178.js
@@ -3,7 +3,5 @@
 // found in the LICENSE file.
 
 assertThrows(() => {
-  new class extends Object {
-    constructor() { (() => delete super[super()])(); }
-  }
+  try { throw {} } catch({a=b, b}) { a+b }

[adamk, 2016/07/12 21:15:22]

Can you also add a test case where we do a hole check but it passes? Something
like:

try { throw {a: 42} } catch ({a, b = a}) { assertEquals(42, b) }

 }, ReferenceError);