Add functions for setting an environment and rebinding a use.

runtime/vm/flow_graph_inliner.cc

 // 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.
 
 #include "vm/flow_graph_inliner.h"
 
 #include "vm/compiler.h"
 #include "vm/flags.h"
 #include "vm/flow_graph.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 555 matching lines @@
         for (intptr_t i = 0; i < arguments->length(); ++i) {
           Definition* stub = param_stubs[i];
           Value* actual = (*arguments)[i];
           if (actual != NULL) stub->ReplaceUsesWith(actual->definition());
         }
 
         // Remove push arguments of the call.
         for (intptr_t i = 0; i < call->ArgumentCount(); ++i) {
           PushArgumentInstr* push = call->PushArgumentAt(i);
           push->ReplaceUsesWith(push->value()->definition());
-          push->UnuseAllInputs();
           push->RemoveFromGraph();
         }
 
         // Replace remaining constants with uses by constants in the caller's
         // initial definitions.
         GrowableArray<Definition*>* defns =
             callee_graph->graph_entry()->initial_definitions();
         for (intptr_t i = 0; i < defns->length(); ++i) {
           ConstantInstr* constant = (*defns)[i]->AsConstant();
           if ((constant != NULL) && constant->HasUses()) {
@@ skipping 282 matching lines @@
         OS::Print("After Inlining of %s\n", flow_graph_->
                   parsed_function().function().ToFullyQualifiedCString());
         FlowGraphPrinter printer(*flow_graph_);
         printer.PrintBlocks();
       }
     }
   }
 }
 
 }  // namespace dart