Less direct use of JavaScriptBackend in ProgramBuilder

pkg/compiler/lib/src/js_backend/backend.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 js_backend.backend;
 
 import 'package:js_runtime/shared/embedded_names.dart' as embeddedNames;
 
 import '../common.dart';
 import '../common/backend_api.dart'
@@ skipping 1180 matching lines @@
     _closedWorldCache = value;
   }
 
   /// Called when the compiler starts running the codegen enqueuer. The
   /// [WorldImpact] of enabled backend features is returned.
   WorldImpact onCodegenStart(
       ClosedWorld closedWorld, CodegenWorldBuilder codegenWorldBuilder) {
     _closedWorld = closedWorld;
     _namer = determineNamer(closedWorld, codegenWorldBuilder);
     tracer = new Tracer(closedWorld, namer, compiler);
-    _rtiEncoder = _namer.rtiEncoder = new _RuntimeTypesEncoder(namer, commonElements);
+    _rtiEncoder =
+        _namer.rtiEncoder = new _RuntimeTypesEncoder(namer, commonElements);
     emitter.createEmitter(namer, closedWorld, codegenWorldBuilder);
     _codegenImpactTransformer = new CodegenImpactTransformer(
         compiler.options,
         compiler.elementEnvironment,
         commonElements,
         impacts,
         checkedModeHelpers,
         nativeData,
         backendUsage,
         rtiNeed,
@@ skipping 396 matching lines @@
 
   bool canUseAliasedSuperMember(MemberEntity member, Selector selector) {
     return !selector.isGetter;
   }
 
   /// Returns `true` if [member] is called from a subclass via `super`.
   bool isAliasedSuperMember(MemberEntity member) {
     return _aliasedSuperMembers.contains(member);
   }
 }