Add support for converted closures with explicit contexts to VM

pkg/kernel/lib/transformations/closure/converter.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.
 
 library kernel.transformations.closure.converter;
 
 import '../../ast.dart'
     show
         Arguments,
         Block,
@@ skipping 218 matching lines @@
       body = new Block(<Statement>[body]);
       function.body = function.body.parent = body;
     }
     return new BlockRewriter(body);
   }
 
   bool isObject(DartType type) {
     return type is InterfaceType && type.classNode.supertype == null;
   }
 
+  TreeNode visitField(Field node) {
+    currentMember = node;
+    context = new NoContext(this);
+    node = super.visitField(node);
+    context = null;
+    currentMember = null;
+    return node;
+  }
+
   Expression handleLocalFunction(FunctionNode function) {
     FunctionNode enclosingFunction = currentFunction;
     Map<TypeParameter, DartType> enclosingTypeSubstitution = typeSubstitution;
     currentFunction = function;
     Statement body = function.body;
     assert(body != null);
 
     rewriter = makeRewriterForBody(function);
 
     VariableDeclaration contextVariable =
@@ skipping 174 matching lines @@
         .forEach(extendContextWith);
     assert(node.body != null);
     node.body = node.body.accept(this);
     node.body.parent = node;
     return node;
   }
 
   TreeNode visitBlock(Block node) {
     return saveContext(() {
       BlockRewriter blockRewriter = rewriter = rewriter.forNestedBlock(node);
-      blockRewriter.transformStatements(node, this);
+      blockRewriter.transformStatements(this);
       return node;
     });
   }
 
   TreeNode visitVariableDeclaration(VariableDeclaration node) {
     node.transformChildren(this);
 
     if (!capturedVariables.contains(node)) return node;
     if (node.initializer == null && node.parent is FunctionNode) {
       // If the variable is a function parameter and doesn't have an
@@ skipping 249 matching lines @@
     copy.function.body.parent = copy.function;
     return copy;
   }
 
   void addGetterForwarder(Name name, Procedure getter) {
     assert(getter.isGetter);
     newClassMembers
         .add(copyWithBody(getter, forwardToThisProperty(getter))..name = name);
   }
 }