Set up a stub pipline for using the new cps-based ir to generate js.

pkg/compiler/lib/src/compiler.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.
 
 part of dart2js;
 
 /**
  * If true, print a warning for each method that was resolved, but not
  * compiled.
  */
@@ skipping 698 matching lines @@
   final bool showPackageWarnings;
 
   /// `true` if the last diagnostic was filtered, in which case the
   /// accompanying info message should be filtered as well.
   bool lastDiagnosticWasFiltered = false;
 
   /// Map containing information about the warnings and hints that have been
   /// suppressed for each library.
   Map<Uri, SuppressionInfo> suppressedWarnings = <Uri, SuppressionInfo>{};
 
+  static const bool USE_CPS_IR = const bool.fromEnvironment("USE_CPS_IR");

[floitsch, 2014/11/12 11:03:19]

Just move it to js_backend/backend.dart unless you think other parts of dart2js
need to have access to it. (But they shouldn't).

[sigurdm, 2014/11/13 08:29:41]

Done.

+
   final bool suppressWarnings;
 
   /// `true` if async/await features are supported.
   final bool enableAsyncAwait;
 
   /// If `true`, some values are cached for reuse in incremental compilation.
   /// Incremental compilation is basically calling [run] more than once.
   final bool hasIncrementalSupport;
 
   api.CompilerOutputProvider outputProvider;
@@ skipping 1446 matching lines @@
   int warnings = 0;
   int hints = 0;
 }
 
 class GenericTask extends CompilerTask {
   final String name;
 
   GenericTask(this.name, Compiler compiler)
       : super(compiler);
 }