Add Vector type to Kernel

pkg/kernel/lib/frontend/accessors.dart

 // Copyright (c) 2016, 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.
 
 /// A library to help transform compounds and null-aware accessors into
 /// let expressions.
 library kernel.frontend.accessors;
 
 import '../ast.dart';
 
@@ skipping 237 matching lines @@
     return builtGetter = new MethodInvocation(receiverAccess(), _indexGet,
         new Arguments(<Expression>[indexAccess()]), getter);
   }
 
   _makeWrite(Expression value, bool voidContext) {
     if (!voidContext) return _makeWriteAndReturn(value);
     return new MethodInvocation(receiverAccess(), _indexSet,
         new Arguments(<Expression>[indexAccess(), value]), setter);
   }
 
+  // TODO(dmitryas): remove this method after the "[]=" operator of the Context
+  // class is made to return a value.
   _makeWriteAndReturn(Expression value) {
     // The call to []= does not return the value like direct-style assignments
     // do.  We need to bind the value in a let.
     var valueVariable = new VariableDeclaration.forValue(value);
     var dummy = new VariableDeclaration.forValue(new MethodInvocation(
         receiverAccess(),
         _indexSet,
         new Arguments(
             <Expression>[indexAccess(), new VariableGet(valueVariable)]),
         setter));
@@ skipping 159 matching lines @@
 
 VariableDeclaration makeOrReuseVariable(Expression value) {
   // TODO: Devise a way to remember if a variable declaration was reused
   // or is fresh (hence needs a let binding).
   return new VariableDeclaration.forValue(value);
 }
 
 Expression wrapInvalid(Expression e) {
   return new Let(new VariableDeclaration.forValue(e), new InvalidExpression());
 }