X87: Eliminate redundant descriptor ElementTransitionAndStoreDescriptor.

src/x87/interface-descriptors-x87.cc

Index: src/x87/interface-descriptors-x87.cc
diff --git a/src/x87/interface-descriptors-x87.cc b/src/x87/interface-descriptors-x87.cc
index 279b42677c1e84cf0b09561935a05ff3508313cd..333564e09995afffc834146186bd7a14b4567cf8 100644
--- a/src/x87/interface-descriptors-x87.cc
+++ b/src/x87/interface-descriptors-x87.cc
@@ -46,11 +46,6 @@ const Register StoreGlobalViaContextDescriptor::NameRegister() { return ecx; }
 const Register StoreGlobalViaContextDescriptor::ValueRegister() { return eax; }
 
 
-const Register ElementTransitionAndStoreDescriptor::MapRegister() {
-  return ebx;
-}
-
-
 const Register InstanceofDescriptor::left() { return eax; }
 const Register InstanceofDescriptor::right() { return edx; }