Fix KernelEquivalence.entityEquivalence for equi-named instance/top-level members

tests/compiler/dart2js/kernel/closed_world2_test.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.
 
 // Partial test that the closed world computed from [WorldImpact]s derived from
 // kernel is equivalent to the original computed from resolution.
 library dart2js.kernel.closed_world2_test;
 
 import 'dart:async';
 
@@ skipping 54 matching lines @@
 class Mixin {
   method1() {}
   method2() {}
   method3() {}
 }
 class Class1 = Object with Mixin;
 class Class2 extends Object with Mixin {
   method3() {}
 }
  
+method1() {} // Deliberately the same name as the instance member in Mixin.
 
 @NoInline()
 main() {
   print('Hello World');
   ''.contains; // Trigger member closurization.
   new Element.div();
   new ClassWithSetter().setter = null;
   new Class1().method1();
   new Class2().method2();
   new Class2().method3();
   null is List<int>;
+  method1(); // Both top level and instance method named 'method1' are live.
 }
 '''
 };
 
 main(List<String> args) {
   asyncTest(() async {
     await mainInternal(args);
   });
 }
 
-Future mainInternal(List<String> args,
+enum ResultKind { crashes, errors, warnings, success, failure }
+
+Future<ResultKind> mainInternal(List<String> args,
     {bool skipWarnings: false, bool skipErrors: false}) async {
   Arguments arguments = new Arguments.from(args);
   Uri entryPoint;
   Map<String, String> memorySourceFiles;
   if (arguments.uri != null) {
     entryPoint = arguments.uri;
     memorySourceFiles = const <String, String>{};
   } else {
     entryPoint = Uri.parse('memory:main.dart');
     memorySourceFiles = SOURCE;
   }
 
   enableDebugMode();
 
   print('---- analyze-only ------------------------------------------------');
   DiagnosticCollector collector = new DiagnosticCollector();
   Compiler compiler1 = compilerFor(
       entryPoint: entryPoint,
       memorySourceFiles: memorySourceFiles,
       diagnosticHandler: collector,
       options: [Flags.analyzeOnly, Flags.enableAssertMessage]);
   ElementResolutionWorldBuilder.useInstantiationMap = true;
   compiler1.resolution.retainCachesForTesting = true;
   await compiler1.run(entryPoint);
+  if (collector.crashes.isNotEmpty) {
+    print('Skipping due to crashes.');
+    return ResultKind.crashes;
+  }
   if (collector.errors.isNotEmpty && skipErrors) {
     print('Skipping due to errors.');
-    return;
+    return ResultKind.errors;
   }
   if (collector.warnings.isNotEmpty && skipWarnings) {
     print('Skipping due to warnings.');
-    return;
+    return ResultKind.warnings;
   }
   Expect.isFalse(compiler1.compilationFailed);
   ResolutionEnqueuer enqueuer1 = compiler1.enqueuer.resolution;
   BackendUsage backendUsage1 = compiler1.backend.backendUsage;
   ClosedWorld closedWorld1 = compiler1.resolutionWorldBuilder.closeWorld();
 
   print('---- analyze-all -------------------------------------------------');
   Compiler compiler = compilerFor(
       entryPoint: entryPoint,
       memorySourceFiles: memorySourceFiles,
@@ skipping 34 matching lines @@
   checkBackendUsage(backendUsage1, backendUsage2, equivalence);
 
   checkResolutionEnqueuers(backendUsage1, backendUsage2, enqueuer1, enqueuer2,
       elementEquivalence: equivalence.entityEquivalence,
       typeEquivalence: (ResolutionDartType a, DartType b) {
     return equivalence.typeEquivalence(unalias(a), b);
   }, elementFilter: elementFilter, verbose: arguments.verbose);
 
   checkClosedWorlds(closedWorld1, closedWorld2, equivalence.entityEquivalence,
       verbose: arguments.verbose);
+
+  return ResultKind.success;
 }
 
 List createKernelResolutionEnqueuerListener(
     CompilerOptions options,
     DiagnosticReporter reporter,
     DeferredLoadTask deferredLoadTask,
     KernelToElementMap elementMap,
     NativeBasicData nativeBasicData) {
   ElementEnvironment elementEnvironment = elementMap.elementEnvironment;
   CommonElements commonElements = elementMap.commonElements;
@@ skipping 168 matching lines @@
 
   MemoryDillLibraryLoaderTask(KernelToElementMap elementMap,
       DiagnosticReporter reporter, Measurer measurer, this.program)
       : super(elementMap, null, null, reporter, measurer);
 
   Future<LoadedLibraries> loadLibrary(Uri resolvedUri,
       {bool skipFileWithPartOfTag: false}) async {
     return createLoadedLibraries(program);
   }
 }