Add option to suppress type-check whitelisting

pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/errors.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 part of dart._runtime;
 
 bool _trapRuntimeErrors = true;
+bool _ignoreWhitelistedErrors = true;
 
 // Override, e.g., for testing
 void trapRuntimeErrors(bool flag) {
   _trapRuntimeErrors = flag;
 }
 
+void ignoreWhitelistedErrors(bool flag) {
+  _ignoreWhitelistedErrors = flag;
+}
+
 throwCastError(object, actual, type) => JS('', '''(() => {
   var found = $typeName($actual);
   var expected = $typeName($type);
   if ($_trapRuntimeErrors) debugger;
   $throw_(new $CastErrorImplementation($object, found, expected));
 })()''');
 
 throwTypeError(object, actual, type) => JS('', '''(() => {
   var found = $typeName($actual);
   var expected = $typeName($type);
@@ skipping 29 matching lines @@
 })()''');
 
 throwNullValueError() => JS('', '''(() => {
   // TODO(vsm): Per spec, we should throw an NSM here.  Technically, we ought
   // to thread through method info, but that uglifies the code and can't
   // actually be queried ... it only affects how the error is printed.
   if ($_trapRuntimeErrors) debugger;
   $throw_(new $NoSuchMethodError(null,
       new $Symbol('<Unexpected Null Value>'), null, null, null));
 })()''');