Get rid of a useless helper method in the register allocator.

src/hydrogen.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 7311 matching lines @@
       }
     }
     int parent_index = -1;
     if (range->IsChild()) {
       parent_index = range->parent()->id();
     } else {
       parent_index = range->id();
     }
     LOperand* op = range->FirstHint();
     int hint_index = -1;
-    if (op != NULL && op->IsUnallocated()) hint_index = op->VirtualRegister();
+    if (op != NULL && op->IsUnallocated()) {
+      hint_index = LUnallocated::cast(op)->virtual_register();
+    }
     trace_.Add(" %d %d", parent_index, hint_index);
     UseInterval* cur_interval = range->first_interval();
     while (cur_interval != NULL && range->Covers(cur_interval->start())) {
       trace_.Add(" [%d, %d[",
                  cur_interval->start().Value(),
                  cur_interval->end().Value());
       cur_interval = cur_interval->next();
     }
 
     UsePosition* current_pos = range->first_pos();
@@ skipping 110 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal