dart2js: Rename old emitter to full emitter and make it its own library.

pkg/compiler/lib/src/js_emitter/full_emitter/nsm_emitter.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.js_emitter;
+part of dart2js.js_emitter.full_emitter;
 
 class NsmEmitter extends CodeEmitterHelper {
   final List<Selector> trivialNsmHandlers = <Selector>[];
 
   /// If this is true then we can generate the noSuchMethod handlers at startup
   /// time, instead of them being emitted as part of the Object class.
   bool get generateTrivialNsmHandlers => true;
 
   // If we need fewer than this many noSuchMethod handlers we can save space by
   // just emitting them in JS, rather than emitting the JS needed to generate
@@ skipping 366 matching lines @@
   }
 
   String get value {
     if (_cachedValue == null) {
       _cachedValue = _computeDiffEncoding();
     }
 
     return _cachedValue;
   }
 }