Create Namer and Emitter on codegen start.

pkg/dart2js_incremental/lib/caching_compiler.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 dart2js_incremental;
 
 /// Do not call this method directly. It will be made private.
 // TODO(ahe): Make this method private.
 Future<CompilerImpl> reuseCompiler(
     {CompilerDiagnostics diagnosticHandler,
@@ skipping 50 matching lines @@
         outputProvider,
         diagnosticHandler,
         new CompilerOptions.parse(
             libraryRoot: libraryRoot,
             packageRoot: packageRoot,
             packageConfig: packageConfig,
             options: options,
             environment: environment));
     backend = compiler.backend;
 
-    full.Emitter emitter = backend.emitter.emitter;
-
-    // Much like a scout, an incremental compiler is always prepared. For
-    // mixins, classes, and lazy statics, at least.
-    emitter
-        ..needsClassSupport = true
-        ..needsMixinSupport = true
-        ..needsLazyInitializer = true
-        ..needsStructuredMemberInfo = true;
-
     Uri core = Uri.parse("dart:core");
 
     return compiler.setupSdk().then((_) {
       return compiler.libraryLoader.loadLibrary(core).then((_) {
         // Likewise, always be prepared for runtimeType support.
         // TODO(johnniwinther): Add global switch to force RTI.
         compiler.resolverWorld.hasRuntimeTypeSupport = true;
         compiler.enqueuer.resolution.applyImpact(backend.registerRuntimeType());
         return compiler;
       });
@@ skipping 99 matching lines @@
   final Map<String, String> output = new Map<String, String>();
 
   EventSink<String> createEventSink(String name, String extension) {
     return new StringEventSink((String data) {
       output['$name.$extension'] = data;
     });
   }
 
   String operator[] (String key) => output[key];
 }