Support creating elements from IR nodes in JsKernelToElementMap

pkg/compiler/lib/src/kernel/kelements.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.
 
 /// Entity model for elements derived from Kernel IR.
 
 import '../elements/entities.dart';
 import '../elements/names.dart';
 import '../elements/types.dart';
 import 'elements.dart';
 
+const String kElementPrefix = 'k';
+
 class KLibrary implements IndexedLibrary {
   /// Library index used for fast lookup in [KernelWorldBuilder].
   final int libraryIndex;
   final String name;
   final Uri canonicalUri;
 
   KLibrary(this.libraryIndex, this.name, this.canonicalUri);
 
-  String toString() => 'library($name)';
+  String toString() => '${kElementPrefix}library($name)';
 }
 
 class KClass implements IndexedClass {
   final KLibrary library;
 
   /// Class index used for fast lookup in [KernelWorldBuilder].
   final int classIndex;
 
   final String name;
   final bool isAbstract;
 
   KClass(this.library, this.classIndex, this.name, {this.isAbstract});
 
   @override
   bool get isClosure => false;
 
-  String toString() => 'class($name)';
+  String toString() => '${kElementPrefix}class($name)';
 }
 
 abstract class KMember implements IndexedMember {
   /// Member index used for fast lookup in [KernelWorldBuilder].
   final int memberIndex;
   final KLibrary library;
   final KClass enclosingClass;
   final Name _name;
   final bool _isStatic;
 
@@ skipping 33 matching lines @@
   bool get isInstanceMember => enclosingClass != null && !_isStatic;
 
   @override
   bool get isStatic => enclosingClass != null && _isStatic;
 
   @override
   bool get isTopLevel => enclosingClass == null;
 
   String get _kind;
 
-  String toString() =>
-      '$_kind(${enclosingClass != null ? '${enclosingClass.name}.' : ''}$name)';
+  String toString() => '${kElementPrefix}$_kind'
+      '(${enclosingClass != null ? '${enclosingClass.name}.' : ''}$name)';
 }
 
 abstract class KFunction extends KMember
     implements FunctionEntity, IndexedFunction {
   final ParameterStructure parameterStructure;
   final bool isExternal;
   final AsyncMarker asyncMarker;
 
   KFunction(int memberIndex, KLibrary library, KClass enclosingClass, Name name,
       this.parameterStructure, this.asyncMarker,
@@ skipping 123 matching lines @@
   String get _kind => 'field';
 }
 
 class KTypeVariable implements TypeVariableEntity {
   final Entity typeDeclaration;
   final String name;
   final int index;
 
   KTypeVariable(this.typeDeclaration, this.name, this.index);
 
-  String toString() => 'type_variable(${typeDeclaration.name}.$name)';
+  String toString() =>
+      '${kElementPrefix}type_variable(${typeDeclaration.name}.$name)';
 }
 
 class KLocalFunction implements Local {
   final String name;
   final MemberEntity memberContext;
   final Entity executableContext;
   final FunctionType functionType;
 
   KLocalFunction(
       this.name, this.memberContext, this.executableContext, this.functionType);
 
   String toString() =>
-      'local_function(${memberContext.name}.${name ?? '<anonymous>'})';
+      '${kElementPrefix}local_function(${memberContext.name}.${name ?? '<anonymous>'})';
 }