Experimental support for RegExp lookbehind.

src/regexp/ia32/regexp-macro-assembler-ia32.h

Index: src/regexp/ia32/regexp-macro-assembler-ia32.h
diff --git a/src/regexp/ia32/regexp-macro-assembler-ia32.h b/src/regexp/ia32/regexp-macro-assembler-ia32.h
index 06b9699d01eea59b5b00b4f2905a09643bd42d64..92c2381a00e10cf4c4324e085f032c3d62791d83 100644
--- a/src/regexp/ia32/regexp-macro-assembler-ia32.h
+++ b/src/regexp/ia32/regexp-macro-assembler-ia32.h
@@ -33,9 +33,11 @@ class RegExpMacroAssemblerIA32: public NativeRegExpMacroAssembler {
   // A "greedy loop" is a loop that is both greedy and with a simple
   // body. It has a particularly simple implementation.
   virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
-  virtual void CheckNotAtStart(Label* on_not_at_start);
-  virtual void CheckNotBackReference(int start_reg, Label* on_no_match);
+  virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start);
+  virtual void CheckNotBackReference(int start_reg, bool read_backward,
+                                     Label* on_no_match);
   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
+                                               bool read_backward,
                                                Label* on_no_match);
   virtual void CheckNotCharacter(uint32_t c, Label* on_not_equal);
   virtual void CheckNotCharacterAfterAnd(uint32_t c,