Add KernelWorldBuilder and KElement model.

pkg/compiler/lib/src/ssa/nodes.dart

 // Copyright (c) 2012, 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 '../closure.dart';
 import '../common.dart';
 import '../common/backend_api.dart' show BackendClasses;
 import '../compiler.dart' show Compiler;
 import '../constants/constant_system.dart';
 import '../constants/values.dart';
-import '../elements/elements.dart'
-    show JumpTarget, LabelDefinition;
+import '../elements/elements.dart' show JumpTarget, LabelDefinition;
 import '../elements/entities.dart';
 import '../elements/types.dart';
 import '../io/source_information.dart';
 import '../js/js.dart' as js;
 import '../js_backend/js_backend.dart';
 import '../native/native.dart' as native;
 import '../tree/dartstring.dart' as ast;
 import '../types/constants.dart' show computeTypeMask;
 import '../types/types.dart';
 import '../universe/selector.dart' show Selector;
@@ skipping 1322 matching lines @@
 
   HInstruction convertType(ClosedWorld closedWorld, DartType type, int kind) {
     if (type == null) return this;
     type = type.unaliased;
     // Only the builder knows how to create [HTypeConversion]
     // instructions with generics. It has the generic type context
     // available.
     assert(!type.isTypeVariable);
     assert(type.treatAsRaw || type.isFunctionType);
     if (type.isDynamic) return this;
-    if (type.isObject) return this;
+    if (type == closedWorld.commonElements.objectType) return this;
     if (type.isVoid || type.isFunctionType || type.isMalformed) {
       return new HTypeConversion(
           type, kind, closedWorld.commonMasks.dynamicType, this);
     }
     assert(type.isInterfaceType);
     if (kind == HTypeConversion.BOOLEAN_CONVERSION_CHECK) {
       // Boolean conversion checks work on non-nullable booleans.
       return new HTypeConversion(
           type, kind, closedWorld.commonMasks.boolType, this);
     } else if (kind == HTypeConversion.CHECKED_MODE_CHECK && !type.treatAsRaw) {
@@ skipping 2105 matching lines @@
 class HDynamicType extends HRuntimeType {
   HDynamicType(DynamicType dartType, TypeMask instructionType)
       : super(const <HInstruction>[], dartType, instructionType);
 
   accept(HVisitor visitor) => visitor.visitDynamicType(this);
 
   int typeCode() => HInstruction.DYNAMIC_TYPE_TYPECODE;
 
   bool typeEquals(HInstruction other) => other is HDynamicType;
 }