Refactor BackendHelpers to be reusageable with KernelWorldBuilder

pkg/compiler/lib/src/js_emitter/program_builder/program_builder.dart

 // Copyright (c) 2014, 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.js_emitter.program_builder;
 
 import '../../closure.dart' show ClosureFieldElement;
 import '../../common.dart';
 import '../../common/names.dart' show Names, Selectors;
 import '../../compiler.dart' show Compiler;
@@ skipping 801 matching lines @@
         Class cls = _classes[element];
         if (cls != null) cls.isEager = true;
       }
     }
   }
 
   Iterable<StaticStubMethod> _generateGetInterceptorMethods() {
     InterceptorStubGenerator stubGenerator =
         new InterceptorStubGenerator(_compiler, namer, backend, closedWorld);
 
-    String holderName = namer.globalObjectFor(helpers.interceptorsLibrary);
+    String holderName =
+        namer.globalObjectForLibrary(helpers.interceptorsLibrary);
     // TODO(floitsch): we shouldn't update the registry in the middle of
     // generating the interceptor methods.
     Holder holder = _registry.registerHolder(holderName);
 
     Map<js.Name, Set<ClassElement>> specializedGetInterceptors =
         backend.specializedGetInterceptors;
     List<js.Name> names = specializedGetInterceptors.keys.toList()..sort();
     return names.map((js.Name name) {
       Set<ClassElement> classes = specializedGetInterceptors[name];
       js.Expression code = stubGenerator.generateGetInterceptorMethod(classes);
@@ skipping 43 matching lines @@
           needsCheckedSetter));
     });
 
     return fields;
   }
 
   Iterable<StaticStubMethod> _generateOneShotInterceptors() {
     InterceptorStubGenerator stubGenerator =
         new InterceptorStubGenerator(_compiler, namer, backend, closedWorld);
 
-    String holderName = namer.globalObjectFor(helpers.interceptorsLibrary);
+    String holderName =
+        namer.globalObjectForLibrary(helpers.interceptorsLibrary);
     // TODO(floitsch): we shouldn't update the registry in the middle of
     // generating the interceptor methods.
     Holder holder = _registry.registerHolder(holderName);
 
     List<js.Name> names = backend.oneShotInterceptors.keys.toList()..sort();
     return names.map((js.Name name) {
       js.Expression code = stubGenerator.generateOneShotInterceptor(name);
       return new StaticStubMethod(name, holder, code);
     });
   }
@@ skipping 64 matching lines @@
       Constant constant = new Constant(name, holder, constantValue);
       _constants[constantValue] = constant;
     }
   }
 
   Holder _registerStaticStateHolder() {
     return _registry.registerHolder(namer.staticStateHolder,
         isStaticStateHolder: true);
   }
 }