Split KernelToElementMap mixins to match interfaces

pkg/compiler/lib/src/ssa/kernel_ast_adapter.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';
 import '../common.dart';
 import '../compiler.dart';
 import '../constants/expressions.dart';
 import '../constants/values.dart';
 import '../common_elements.dart';
 import '../elements/elements.dart';
 import '../elements/entities.dart';
 import '../elements/jumps.dart';
 import '../elements/modelx.dart';
 import '../elements/resolution_types.dart';
 import '../elements/types.dart';
 import '../js_backend/js_backend.dart';
 import '../kernel/element_map.dart';
+import '../kernel/element_map_mixins.dart';
 import '../kernel/kernel.dart';
 import '../native/native.dart' as native;
 import '../resolution/tree_elements.dart';
 import '../tree/tree.dart' as ast;
 import '../types/masks.dart';
 import '../types/types.dart';
 import '../universe/selector.dart';
 import '../world.dart';
 import 'graph_builder.dart';
 import 'jump_handler.dart' show SwitchCaseJumpHandler;
 import 'locals_handler.dart';
 import 'types.dart';
 
 /// A helper class that abstracts all accesses of the AST from Kernel nodes.
 ///
 /// The goal is to remove all need for the AST from the Kernel SSA builder.
-class KernelAstAdapter extends KernelToElementMapMixin
-    implements KernelToLocalsMap, KernelToElementMapForImpact {
+class KernelAstAdapter extends KernelToElementMapBaseMixin
+    with KernelToElementMapForBuildingMixin, KernelToElementMapForImpactMixin
+    implements KernelToLocalsMap {
   final Kernel kernel;
   final JavaScriptBackend _backend;
   final Map<ir.Node, ast.Node> _nodeToAst;
   final Map<ir.Node, Element> _nodeToElement;
   final Map<ir.VariableDeclaration, SyntheticLocal> _syntheticLocals =
       <ir.VariableDeclaration, SyntheticLocal>{};
   // TODO(efortuna): In an ideal world the TreeNodes should be some common
   // interface we create for both ir.Statements and ir.SwitchCase (the
   // ContinueSwitchStatement's target is a SwitchCase) rather than general
   // TreeNode. Talking to Asger about this.
@@ skipping 621 matching lines @@
   TypeMask selectorTypeOf(Selector selector, TypeMask mask) {
     return TypeMaskFactory.inferredTypeForSelector(
         selector, mask, _globalInferenceResults);
   }
 
   TypeMask typeFromNativeBehavior(
       native.NativeBehavior nativeBehavior, ClosedWorld closedWorld) {
     return TypeMaskFactory.fromNativeBehavior(nativeBehavior, closedWorld);
   }
 }