Revert of Add errors for declarations which conflict with catch parameters.

test/mjsunit/es6/block-conflicts.js

 // Copyright 2011 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.
 
 // Test for conflicting variable bindings.
 
 "use strict";
 
 function CheckException(e) {
   var string = e.toString();
@@ skipping 152 matching lines @@
 // Test conflicting catch/var bindings.
 for (var v = 0; v < varbinds.length; ++v) {
   TestNoConflict('try {} catch(x) {' + varbinds[v] + '}');
 }
 
 // Test conflicting parameter/var bindings.
 for (var v = 0; v < varbinds.length; ++v) {
   TestNoConflict('(function (x) {' + varbinds[v] + '})();');
 }
 
+// Test conflicting catch/function bindings.
+TestNoConflict('try {} catch(x) {' + funbind + '}');
+
 // Test conflicting parameter/function bindings.
 TestNoConflict('(function (x) {' + funbind + '})();');