Irregexp-ia32: Fixed backref-matching (works, and advances current position).

src/jsregexp.cc

Index: src/jsregexp.cc
diff --git a/src/jsregexp.cc b/src/jsregexp.cc
index 05b8aa0f82bf214265f0832036e4d35099d0c961..3046b96afa650561afaa37163a4fdd81a5ee6515 100644
--- a/src/jsregexp.cc
+++ b/src/jsregexp.cc
@@ -1541,10 +1541,6 @@ bool ActionNode::Emit(RegExpCompiler* compiler) {
 bool BackReferenceNode::Emit(RegExpCompiler* compiler) {
   RegExpMacroAssembler* macro = compiler->macro_assembler();
   Bind(macro);
-  // Check whether the registers are uninitialized and always
-  // succeed if they are.
-  macro->IfRegisterLT(start_reg_, 0, on_success()->label());
-  macro->IfRegisterLT(end_reg_, 0, on_success()->label());
   ASSERT_EQ(start_reg_ + 1, end_reg_);
   if (info()->at_end) {
     // If we are constrained to match at the end of the input then succeed