Refactor LoopHandler to avoid calling KernelAstAdapter.getNode

pkg/compiler/lib/src/ssa/loop_handler.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.
 
 import 'package:kernel/ast.dart' as ir;
 
+import '../closure.dart' show LoopClosureRepresentationInfo;
 import '../elements/elements.dart' show JumpTarget, LabelDefinition;
 import '../io/source_information.dart';
 import '../tree/tree.dart' as ast;
-import '../closure.dart' show LoopClosureRepresentationInfo;
 
 import 'builder.dart';
 import 'builder_kernel.dart';
 import 'graph_builder.dart';
 import 'jump_handler.dart';
 import 'kernel_ast_adapter.dart';
 import 'locals_handler.dart';
 import 'nodes.dart';
 
 /// Builds the SSA graph for loop nodes.
@@ skipping 332 matching lines @@
   KernelLoopHandler(KernelSsaBuilder builder)
       : this.builder = builder,
         super(builder);
 
   @override
   JumpHandler createJumpHandler(ir.TreeNode node, {bool isLoopJump}) =>
       builder.createJumpHandler(node, isLoopJump: isLoopJump);
 
   @override
   JumpTarget getTargetDefinition(ir.TreeNode node) =>
-      astAdapter.getJumpTarget(node);
+      builder.localsMap.getJumpTarget(node);
 
   @override
   int loopKind(ir.TreeNode node) => node.accept(new _KernelLoopTypeVisitor());
 
   // TODO(het): return the actual source information
   @override
   SourceInformation loopSourceInformation(ir.TreeNode node) => null;
 }
 
 class _KernelLoopTypeVisitor extends ir.Visitor<int> {
@@ skipping 12 matching lines @@
       HLoopBlockInformation.DO_WHILE_LOOP;
 
   @override
   int visitForInStatement(ir.ForInStatement node) =>
       HLoopBlockInformation.FOR_IN_LOOP;
 
   @override
   int visitSwitchStatement(ir.SwitchStatement node) =>
       HLoopBlockInformation.SWITCH_CONTINUE_LOOP;
 }