rename `as` helper to make tools happy

lib/runtime/dart_runtime.js

 // 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.
 
 var dart;
 (function (dart) {
   var defineProperty = Object.defineProperty;
   var getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;
   var getOwnPropertyNames = Object.getOwnPropertyNames;
 
@@ skipping 75 matching lines @@
   function dsetindex(obj, index, value) {
     return checkAndCall(obj.set, obj, [index, value], '[]=');
   }
   dart.dsetindex = dindex;
 
   function dbinary(left, op, right) {
     return checkAndCall(left[op], left, [right], op);
   }
   dart.dbinary = dbinary;
 
-  function as(obj, type) {
+  function as_(obj, type) {
     // TODO(vsm): Implement.
     // if (obj == null || is(obj, type)) return obj;
     // throw new core.CastError();
     return obj;
   }
-  dart.as = as;
+  dart.as = as_;
 
   function is(obj, type) {
     // TODO(vsm): Implement.
     throw new core.UnimplementedError();
   }
   dart.is = is;
 
   function isGroundType(type) {
     // TODO(vsm): Implement.
     throw new core.UnimplementedError();
@@ skipping 235 matching lines @@
     var init = this[name];
     var result = void 0;
     if (init) result = init.apply(this, arguments);
     return result === void 0 ? this : result;
   };
   // The initializer for dart.Object
   dart.Object.prototype.Object = function() {};
   dart.Object.prototype.constructor = dart.Object;
 
 })(dart || (dart = {}));