Revert "Use the same registers for StoreIC and KeyedStoreIC."

src/ic.h

Index: src/ic.h
diff --git a/src/ic.h b/src/ic.h
index 262893f3965dadb443509791578306b3fd04021e..47ffd6e529df98b046b18f11eab2d1036be7d925 100644
--- a/src/ic.h
+++ b/src/ic.h
@@ -705,11 +705,6 @@ class KeyedStoreIC: public StoreIC {
   static const Register NameRegister();
   static const Register ValueRegister();
 
-  // The map register isn't part of the normal call specification, but
-  // ElementsTransitionAndStoreStub, used in polymorphic keyed store
-  // stub implementations requires it to be initialized.
-  static const Register MapRegister();
-
   KeyedStoreIC(FrameDepth depth, Isolate* isolate)
       : StoreIC(depth, isolate) {
     ASSERT(target()->is_keyed_store_stub());