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

src/jsregexp.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 379 matching lines @@
   OutSet empty_;
   ZoneSplayTree<Config>* tree() { return &tree_; }
   ZoneSplayTree<Config> tree_;
 };
 
 
 #define FOR_EACH_NODE_TYPE(VISIT)                                    \
   VISIT(End)                                                         \
   VISIT(Action)                                                      \
   VISIT(Choice)                                                      \
-  VISIT(Backreference)                                               \
+  VISIT(BackReference)                                               \
   VISIT(Text)
 
 
 #define FOR_EACH_REG_EXP_TREE_TYPE(VISIT)                            \
   VISIT(Disjunction)                                                 \
   VISIT(Alternative)                                                 \
   VISIT(Assertion)                                                   \
   VISIT(CharacterClass)                                              \
   VISIT(Atom)                                                        \
   VISIT(Quantifier)                                                  \
   VISIT(Capture)                                                     \
   VISIT(Lookahead)                                                   \
-  VISIT(Backreference)                                               \
+  VISIT(BackReference)                                               \
   VISIT(Empty)                                                       \
   VISIT(Text)
 
 
 #define FORWARD_DECLARE(Name) class RegExp##Name;
 FOR_EACH_REG_EXP_TREE_TYPE(FORWARD_DECLARE)
 #undef FORWARD_DECLARE
 
 
 class TextElement {
@@ skipping 170 matching lines @@
   virtual RegExpNode* PropagateInterest(NodeInfo* info);
   RegExpNode* on_failure() { return on_failure_; }
   virtual bool Emit(RegExpCompiler* compiler);
   ZoneList<TextElement>* elements() { return elms_; }
  private:
   RegExpNode* on_failure_;
   ZoneList<TextElement>* elms_;
 };
 
 
-class BackreferenceNode: public SeqRegExpNode {
+class BackReferenceNode: public SeqRegExpNode {
  public:
-  BackreferenceNode(int start_reg,
+  BackReferenceNode(int start_reg,
                     int end_reg,
                     RegExpNode* on_success,
                     RegExpNode* on_failure)
     : SeqRegExpNode(on_success),
       on_failure_(on_failure),
       start_reg_(start_reg),
       end_reg_(end_reg) { }
   virtual void Accept(NodeVisitor* visitor);
   RegExpNode* on_failure() { return on_failure_; }
   int start_register() { return start_reg_; }
   int end_register() { return end_reg_; }
-  virtual bool Emit(RegExpCompiler* compiler) { return false; }
+  virtual bool Emit(RegExpCompiler* compiler);
   virtual RegExpNode* PropagateInterest(NodeInfo* info);
  private:
   RegExpNode* on_failure_;
   int start_reg_;
   int end_reg_;
 };
 
 
 class EndNode: public RegExpNode {
  public:
@@ skipping 133 matching lines @@
   static Handle<FixedArray> Compile(RegExpParseResult* input,
                                     RegExpNode** node_return,
                                     bool ignore_case);
   static void DotPrint(const char* label, RegExpNode* node);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_JSREGEXP_H_