Make dart2js deferred loading work in cps mode.

sdk/lib/_internal/compiler/implementation/use_unused_api.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.
 
 /// This file use methods that aren't used by dart2js.dart, but that we wish to
 /// keep anyway. This might be general API that isn't currently in use,
 /// debugging aids, or API only used for testing (see TODO below).
 
 library dart2js.use_unused_api;
 
@@ skipping 28 matching lines @@
 import 'inferrer/type_graph_inferrer.dart' as type_graph_inferrer;
 
 import 'source_file_provider.dart' as source_file_provider;
 
 import 'ssa/ssa.dart' as ssa;
 
 import 'cps_ir/cps_ir_nodes_sexpr.dart' as cps_ir_nodes_sexpr;
 
 import 'cps_ir/cps_ir_builder.dart' as ir_builder;
 
+import 'js_emitter/js_emitter.dart' as js_emitter;
+
 class ElementVisitor extends elements_visitor.ElementVisitor {
   visitElement(e) {}
 }
 
 void main(List<String> arguments) {
   useApi();
   dart2js.main(arguments);
   useConstant(null, null);
   useNode(null);
   useUtil(null);
   useSetlet(null);
   useImmutableEmptySet(null);
   useElementVisitor(new ElementVisitor());
   useJs(new js.Program(null));
   useJs(new js.Blob(null));
   useJs(new js.NamedFunction(null, null));
   useConcreteTypesInferrer(null);
   useColor();
   useFilenames();
   useSsa(null);
   useCodeBuffer(null);
   usedByTests();
   useElements(null, null, null);
   useIr(null, null, null);
   useCompiler(null);
   useTypes();
+  useCodeEmitterTask(null);
 }
 
 useApi() {
   api.ReadStringFromUri uri;
 }
 
 void useConstant(dart2jslib.Constant constant, dart2jslib.ConstantSystem cs) {
   constant.isObject;
   cs.isBool(constant);
 }
@@ skipping 164 matching lines @@
 }
 
 useCompiler(dart2jslib.Compiler compiler) {
   compiler.libraryLoader.reset();
   compiler.libraryLoader.lookupLibrary(null);
 }
 
 useTypes() {
   new dart_types.ResolvedTypedefType(null, null, null).unalias(null);
 }
+
+useCodeEmitterTask(js_emitter.CodeEmitterTask codeEmitterTask) {
+  codeEmitterTask.clearCspPrecompiledNodes();
+}