Improve the generated code for the instanceof operator.

src/code-stubs.h

 // Copyright 2006-2008 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 26 matching lines @@
   enum Major {
     CallFunction,
     GenericBinaryOp,
     SmiOp,
     Compare,
     RecordWrite,  // Last stub that allows stub calls inside.
     StackCheck,
     UnarySub,
     RevertToNumber,
     ToBoolean,
+    Instanceof,
     CounterOp,
     ArgumentsAccess,
     Runtime,
     CEntry,
     JSEntry,
     GetProperty,   // ARM only
     SetProperty,   // ARM only
     InvokeBuiltin,  // ARM only
     JSExit,        // ARM only
     NUMBER_OF_IDS
@@ skipping 18 matching lines @@
 
  private:
   // Generates the assembler code for the stub.
   virtual void Generate(MacroAssembler* masm) = 0;
 
   // Returns information for computing the number key.
   virtual Major MajorKey() = 0;
   virtual int MinorKey() = 0;
 
   // Returns a name for logging/debugging purposes.
-  virtual const char* GetName() = 0;
+  virtual const char* GetName() { return MajorName(MajorKey()); }
 
 #ifdef DEBUG
   virtual void Print() { PrintF("%s\n", GetName()); }
 #endif
 
   // Computes the key based on major and minor.
   uint32_t GetKey() {
     ASSERT(static_cast<int>(MajorKey()) < NUMBER_OF_IDS);
     return MinorKeyBits::encode(MinorKey()) |
            MajorKeyBits::encode(MajorKey());
   }
 
   bool AllowsStubCalls() { return MajorKey() <= RecordWrite; }
 
   class MajorKeyBits: public BitField<uint32_t, 0, kMajorBits> {};
   class MinorKeyBits: public BitField<uint32_t, kMajorBits, kMinorBits> {};
 
   friend class BreakPointIterator;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_