Only do a full verify after computing dominators.

src/hydrogen.h

 // Copyright 2011 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 265 matching lines @@
   int GetNextValueID(HValue* value) {
     values_.Add(value);
     return values_.length() - 1;
   }
   HValue* LookupValue(int id) const {
     if (id >= 0 && id < values_.length()) return values_[id];
     return NULL;
   }
 
 #ifdef DEBUG
-  void Verify() const;
+  void Verify(bool do_full_verify) const;
 #endif
 
  private:
   void Postorder(HBasicBlock* block,
                  BitVector* visited,
                  ZoneList<HBasicBlock*>* order,
                  HBasicBlock* loop_header);
   void PostorderLoopBlocks(HLoopInformation* loop,
                            BitVector* visited,
                            ZoneList<HBasicBlock*>* order,
@@ skipping 937 matching lines @@
   const char* filename_;
   HeapStringAllocator string_allocator_;
   StringStream trace_;
   int indent_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_