Remove unused function in ia32 code generator

src/ia32/codegen-ia32.cc

Index: src/ia32/codegen-ia32.cc
===================================================================
--- src/ia32/codegen-ia32.cc	(revision 4607)
+++ src/ia32/codegen-ia32.cc	(working copy)
@@ -829,14 +829,6 @@
 }
 
 
-void CodeGenerator::UnloadReference(Reference* ref) {
-  // Pop a reference from the stack while preserving TOS.
-  Comment cmnt(masm_, "[ UnloadReference");
-  frame_->Nip(ref->size());
-  ref->set_unloaded();
-}
-
-
 // ECMA-262, section 9.2, page 30: ToBoolean(). Pop the top of stack and
 // convert it to a boolean in the condition code register or jump to
 // 'false_target'/'true_target' as appropriate.