Fix 56 hints in pkg/compiler

pkg/compiler/lib/src/js_emitter/registry.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.
 
 part of dart2js.js_emitter.program_builder;
 
 /// Maps [LibraryElement]s to their [Element]s.
 ///
 /// Fundamentally, this class nicely encapsulates a
 /// `Map<LibraryElement, List<Element>>`.
@@ skipping 54 matching lines @@
   Iterable<LibrariesMap> get deferredLibrariesMap =>
       _deferredLibrariesMap.values;
 
   // Add one for the main libraries map.
   int get librariesMapCount => _deferredLibrariesMap.length + 1;
 
   LibrariesMap mainLibrariesMap;
 
   Registry(this._compiler);
 
-  bool get _isProgramSplit => _deferredLoadTask.isProgramSplit;
   OutputUnit get _mainOutputUnit => _deferredLoadTask.mainOutputUnit;
 
   LibrariesMap _mapUnitToLibrariesMap(OutputUnit targetUnit) {
     if (targetUnit == _lastOutputUnit) return _lastLibrariesMap;
 
     LibrariesMap result = (targetUnit == _mainOutputUnit)
         ? mainLibrariesMap
         : _deferredLibrariesMap[targetUnit];
 
     assert(result != null);
@@ skipping 26 matching lines @@
 
   void registerConstant(OutputUnit outputUnit, ConstantValue constantValue) {
     // Ignore for now.
   }
 
   Holder registerHolder(String name) {
     return _holdersMap.putIfAbsent(
         name,
         () => new Holder(name, _holdersMap.length));
   }
-}
+}