Adjusts dart2js backend to handle method type arguments.

pkg/compiler/lib/src/ssa/optimize.dart

 // Copyright (c) 2012, 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.
 
 import '../common/codegen.dart' show CodegenWorkItem;
 import '../common/tasks.dart' show CompilerTask;
 import '../compiler.dart' show Compiler;
 import '../constants/constant_system.dart';
 import '../constants/values.dart';
 import '../core_types.dart' show CoreClasses;
@@ skipping 762 matching lines @@
   }
 
   HInstruction removeIfCheckAlwaysSucceeds(HCheck node, TypeMask checkedType) {
     ClassWorld classWorld = compiler.world;
     if (checkedType.containsAll(classWorld)) return node;
     HInstruction input = node.checkedInput;
     TypeMask inputType = input.instructionType;
     return inputType.isInMask(checkedType, classWorld) ? input : node;
   }
 
+  HInstruction removeCheck(HCheck node) => node.checkedInput;
+
   VariableElement findConcreteFieldForDynamicAccess(
       HInstruction receiver, Selector selector) {
     TypeMask receiverType = receiver.instructionType;
     return compiler.world.locateSingleField(selector, receiverType);
   }
 
   HInstruction visitFieldGet(HFieldGet node) {
     if (node.isNullCheck) return node;
     var receiver = node.receiver;
     if (node.element == helpers.jsIndexableLength) {
@@ skipping 1586 matching lines @@
 
     keyedValues.forEach((receiver, values) {
       result.keyedValues[receiver] =
           new Map<HInstruction, HInstruction>.from(values);
     });
 
     result.nonEscapingReceivers.addAll(nonEscapingReceivers);
     return result;
   }
 }