Add back references. Since "back references" is two words...

src/assembler-re2k.cc

 // Copyright 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 193 matching lines @@
 }
 
 
 void Re2kAssembler::CheckCharacterGT(uc16 limit, Label* on_greater) {
   Emit(BC_CHECK_GT);
   Emit16(limit);
   EmitOrLink(on_greater);
 }
 
 
-void Re2kAssembler::CheckBackref(int capture_index,
-                                 Label* on_mismatch) {
-  Emit(BC_CHECK_BACKREF);
-  Emit32(0);
+void Re2kAssembler::CheckNotBackReference(int capture_index,
+                                          Label* on_mismatch) {
+  Emit(BC_CHECK_NOT_BACK_REF);
   Emit(capture_index);
   EmitOrLink(on_mismatch);
 }
 
 
 void Re2kAssembler::CheckRegister(int byte_code,
                                   int reg_index,
                                   uint16_t vs,
                                   Label* on_true) {
   Emit(byte_code);
@@ skipping 83 matching lines @@
   buffer_ = Vector<byte>::New(old_buffer.length() * 2);
   own_buffer_ = true;
   memcpy(buffer_.start(), old_buffer.start(), old_buffer.length());
   if (old_buffer_was_our_own) {
     old_buffer.Dispose();
   }
 }
 
 
 } }  // namespace v8::internal