X87: Eliminate redundant descriptor ElementTransitionAndStoreDescriptor.

port 26ffee2c (r29789).

original commit message:

    It's just the same as StoreTransitionDescriptor.

BUG=

Review URL: https://codereview.chromium.org/1253573004

Cr-Commit-Position: refs/heads/master@{#29831}

src/ic/x87/access-compiler-x87.cc

@@ -32,7 +32,7 @@ Register* PropertyAccessCompiler::store_calling_convention() {
   // receiver, name, scratch1, scratch2, scratch3.
   Register receiver = StoreDescriptor::ReceiverRegister();
   Register name = StoreDescriptor::NameRegister();
-  DCHECK(ebx.is(ElementTransitionAndStoreDescriptor::MapRegister()));
+  DCHECK(ebx.is(StoreTransitionDescriptor::MapRegister()));
   static Register registers[] = {receiver, name, ebx, edi, no_reg};
   return registers;
 }

src/ic/x87/ic-compiler-x87.cc

@@ -69,7 +69,7 @@ Handle<Code> PropertyICCompiler::CompilePolymorphic(MapHandleList* maps,
   // Polymorphic keyed stores may use the map register
   Register map_reg = scratch1();
   DCHECK(kind() != Code::KEYED_STORE_IC ||
-         map_reg.is(ElementTransitionAndStoreDescriptor::MapRegister()));
+         map_reg.is(StoreTransitionDescriptor::MapRegister()));
   __ mov(map_reg, FieldOperand(receiver(), HeapObject::kMapOffset));
   int receiver_count = maps->length();
   int number_of_handled_maps = 0;

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; }