Streamline the CPS IR Visitor interface.

pkg/compiler/lib/src/dart_backend/backend.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 dart_backend;
 
 // TODO(ahe): This class is simply wrong.  This backend should use
 // elements when it can, not AST nodes.  Perhaps a [Map<Element,
 // TreeElements>] is what is needed.
 class ElementAst {
@@ skipping 137 matching lines @@
         .rewrite(cpsDefinition);
     context.traceGraph("Sparse constant propagation", cpsDefinition);
     new RedundantPhiEliminator().rewrite(cpsDefinition);
     context.traceGraph("Redundant phi elimination", cpsDefinition);
     new ShrinkingReducer().rewrite(cpsDefinition);
     context.traceGraph("Shrinking reductions", cpsDefinition);
 
     // Do not rewrite the IR after variable allocation.  Allocation
     // makes decisions based on an approximation of IR variable live
     // ranges that can be invalidated by transforming the IR.
-    new cps_ir.RegisterAllocator().visit(cpsDefinition);
+    new cps_ir.RegisterAllocator(context.internalError).visit(cpsDefinition);
 
     tree_builder.Builder builder =
         new tree_builder.Builder(context.internalError);
     tree_ir.ExecutableDefinition treeDefinition = builder.build(cpsDefinition);
     assert(treeDefinition != null);
     context.traceGraph('Tree builder', treeDefinition);
 
     // Transformations on the Tree IR.
     new StatementRewriter().rewrite(treeDefinition);
     context.traceGraph('Statement rewriter', treeDefinition);
@@ skipping 372 matching lines @@
   }
 
   void traceGraph(String title, var irObject) {
     compiler.tracer.traceGraph(title, irObject);
   }
 
   DartTypes get dartTypes => compiler.types;
 
   InternalErrorFunction get internalError => compiler.internalError;
 }