Implement modular compilation

tool/input_sdk/private/ddc_runtime/runtime.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.
 
 library dart._runtime;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'dart:_foreign_helper' show JS, JSExportName, rest, spread;
 import 'dart:_interceptors' show JSArray;
 import 'dart:_js_helper' show SyncIterable, CastErrorImplementation, getTraceFromException;
 
 part 'classes.dart';
 part 'errors.dart';
 part 'generators.dart';
 part 'operations.dart';
 part 'rtti.dart';
 part 'types.dart';
 part 'utils.dart';
 
-// From dart_utils
-final defineLazyClass = JS('', '$defineLazy');
-final defineLazyProperties = JS('', '$defineLazy');
-final defineLazyClassGeneric = JS('', '$defineLazyProperty');
-
-// Renames
-@JSExportName('as')
-final as_ = JS('', '$cast');
-
-@JSExportName('is')
-final is_ = JS('', '$instanceOf');
-
 @JSExportName('global')
 final global_ = JS('', 'typeof window == "undefined" ? global : window');
 final JsSymbol = JS('', 'Symbol');
 
 // TODO(vsm): This is referenced (as init.globalState) from
 // isolate_helper.dart.  Where should it go?
 // See: https://github.com/dart-lang/dev_compiler/issues/164
 // exports.globalState = null;
 // TODO(ochafik).
 // _js_helper.checkNum = operations.notNull;