Split backend implementation of EnqueuerListener

pkg/compiler/lib/src/world.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.
 
 library dart2js.world;
 
 import 'closure.dart' show ClosureClassElement, SynthesizedCallMethodElementX;
 import 'common/backend_api.dart' show BackendClasses;
 import 'common.dart';
 import 'constants/constant_system.dart';
@@ skipping 1055 matching lines @@
   MemberElement locateSingleElement(Selector selector, TypeMask mask) {
     assert(isClosed);
     mask ??= commonMasks.dynamicType;
     return mask.locateSingleElement(selector, this);
   }
 
   TypeMask extendMaskIfReachesAll(Selector selector, TypeMask mask) {
     assert(isClosed);
     bool canReachAll = true;
     if (mask != null) {
-      canReachAll = _backend.hasInvokeOnSupport &&
+      canReachAll = _backend.backendUsage.isInvokeOnUsed &&
           mask.needsNoSuchMethodHandling(selector, this);
     }
     return canReachAll ? commonMasks.dynamicType : mask;
   }
 
   void addFunctionCalledInLoop(Element element) {
     functionsCalledInLoop.add(element.declaration);
   }
 
   bool isCalledInLoop(Element element) {
@@ skipping 96 matching lines @@
       return getMightBePassedToApply(element.expression);
     }
     return functionsThatMightBePassedToApply.contains(element);
   }
 
   @override
   bool getCurrentlyKnownMightBePassedToApply(Element element) {
     return getMightBePassedToApply(element);
   }
 }