Remove Compiler.mainApp and Compiler.mainFunction

pkg/compiler/lib/src/js_emitter/code_emitter_task.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.js_emitter.code_emitter_task;
 
 import 'package:js_runtime/shared/embedded_names.dart' show JsBuiltin;
 
 import '../common.dart';
 import '../common/tasks.dart' show CompilerTask;
@@ skipping 199 matching lines @@
           backend.rtiEncoder,
           backend.rtiSubstitutions,
           backend.jsInteropAnalysis,
           backend.oneShotInterceptorData,
           backend.customElementsCodegenAnalysis,
           backend.generatedCode,
           namer,
           this,
           closedWorld,
           typeTestRegistry.rtiNeededClasses,
-          compiler.mainFunction,
+          closedWorld.elementEnvironment.mainFunction,
           isMockCompilation: compiler.isMockCompilation);
       int size = emitter.emitProgram(programBuilder);
       // TODO(floitsch): we shouldn't need the `neededClasses` anymore.
       neededClasses = programBuilder.collector.neededClasses;
       return size;
     });
   }
 }
 
 abstract class EmitterFactory {
@@ skipping 99 matching lines @@
   @override
   jsAst.PropertyAccess interceptorClassAccess(ClassEntity element) {
     return globalPropertyAccessForClass(element);
   }
 
   @override
   jsAst.PropertyAccess typeAccess(Entity element) {
     return globalPropertyAccessForType(element);
   }
 }