Reuse RuntimeTypesNeedBuilderImpl and _RuntimeTypesNeed for kernel based elements

pkg/compiler/lib/src/kernel/element_map.dart

 // Copyright (c) 2017, 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 dart2js.kernel.element_map;
 
 import 'package:kernel/ast.dart' as ir;
 
 import '../common.dart';
 import '../common/resolution.dart';
@@ skipping 406 matching lines @@
     _ensureThisAndRawType(cls, env);
     return env.thisType;
   }
 
   InterfaceType _getRawType(KClass cls) {
     _KClassEnv env = _classEnvs[cls.classIndex];
     _ensureThisAndRawType(cls, env);
     return env.rawType;
   }
 
+  InterfaceType _asInstanceOf(InterfaceType type, KClass cls) {
+    OrderedTypeSet orderedTypeSet = _getOrderedTypeSet(type.element);
+    InterfaceType supertype =
+        orderedTypeSet.asInstanceOf(cls, _getHierarchyDepth(cls));
+    if (supertype != null) {
+      supertype = _substByContext(supertype, type);
+    }
+    return supertype;
+  }
+
   void _ensureSupertypes(KClass cls, _KClassEnv env) {
     if (env.orderedTypeSet == null) {
       _ensureThisAndRawType(cls, env);
 
       ir.Class node = env.cls;
 
       if (node.supertype == null) {
         env.orderedTypeSet = new OrderedTypeSet.singleton(env.thisType);
       } else {
         InterfaceType processSupertype(ir.Supertype node) {
@@ skipping 457 matching lines @@
   InterfaceType getThisType(ClassEntity cls) {
     return elementMap._getThisType(cls);
   }
 
   @override
   InterfaceType getRawType(ClassEntity cls) {
     return elementMap._getRawType(cls);
   }
 
   @override
+  bool isGenericClass(ClassEntity cls) {
+    return getThisType(cls).typeArguments.isNotEmpty;
+  }
+
+  @override
   DartType getTypeVariableBound(TypeVariableEntity typeVariable) {
     throw new UnimplementedError(
         'KernelElementEnvironment.getTypeVariableBound');
   }
 
   @override
   InterfaceType createInterfaceType(
       ClassEntity cls, List<DartType> typeArguments) {
     return new InterfaceType(cls, typeArguments);
   }
@@ skipping 368 matching lines @@
   }
 
   InterfaceType getMixinTypeForClass(KClass cls) {
     _KClassEnv env = builder._classEnvs[cls.classIndex];
     ir.Supertype mixedInType = env.cls.mixedInType;
     if (mixedInType == null) return null;
     return builder.createInterfaceType(
         mixedInType.classNode, mixedInType.typeArguments);
   }
 }