Introduce BackendImpact to separate enqueueing from data.

pkg/compiler/lib/src/js_backend/custom_elements_analysis.dart

 // Copyright (c) 2013, 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.
 
 part of js_backend;
 
 /**
  * Support for Custom Elements.
  *
  * The support for custom elements the compiler builds a table that maps the
@@ skipping 56 matching lines @@
       enqueuer.isResolutionQueue ? resolutionJoin : codegenJoin;
 
   void registerInstantiatedClass(ClassElement classElement, Enqueuer enqueuer) {
     classElement.ensureResolved(compiler.resolution);
     if (!Elements.isNativeOrExtendsNative(classElement)) return;
     if (classElement.isMixinApplication) return;
     if (classElement.isAbstract) return;
     joinFor(enqueuer).instantiatedClasses.add(classElement);
   }
 
-  void registerTypeLiteral(DartType type, Registry registry) {
-    assert(registry.isForResolution);
-    // In codegen we see the TypeConstants instead.
-    if (!registry.isForResolution) return;
-
+  void registerTypeLiteral(DartType type) {
     if (type.isInterfaceType) {
       // TODO(sra): If we had a flow query from the type literal expression to
       // the Type argument of the metadata lookup, we could tell if this type
       // literal is really a demand for the metadata.
       resolutionJoin.selectedClasses.add(type.element);
     } else if (type.isTypeVariable) {
       // This is a type parameter of a parameterized class.
       // TODO(sra): Is there a way to determine which types are bound to the
       // parameter?
       resolutionJoin.allClassesSelected = true;
@@ skipping 105 matching lines @@
           result.add(member);
         }
       }
     }
     classElement.forEachMember(selectGenerativeConstructors,
         includeBackendMembers: false,
         includeSuperAndInjectedMembers: false);
     return result;
   }
 }