Revert "Refactor transitioning stores."

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 3ef4599ef0b6a3c57860c8868d9c354a8d790531..1d1da3d38371e65e9e9c92a3ca741598cf9c7fd4 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -4021,12 +4021,33 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
     }
   } else if (representation.IsDouble()) {
     ASSERT(access.IsInobject());
+    ASSERT(!hinstr->has_transition());
     ASSERT(!hinstr->NeedsWriteBarrier());
     XMMRegister value = ToDoubleRegister(instr->value());
     __ movsd(FieldOperand(object, offset), value);
     return;
   }
 
+  if (hinstr->has_transition()) {
+    Handle<Map> transition = hinstr->transition_map();
+    AddDeprecationDependency(transition);
+    if (!hinstr->NeedsWriteBarrierForMap()) {
+      __ Move(FieldOperand(object, HeapObject::kMapOffset), transition);
+    } else {
+      Register temp = ToRegister(instr->temp());
+      __ Move(kScratchRegister, transition);
+      __ movp(FieldOperand(object, HeapObject::kMapOffset), kScratchRegister);
+      // Update the write barrier for the map field.
+      __ RecordWriteField(object,
+                          HeapObject::kMapOffset,
+                          kScratchRegister,
+                          temp,
+                          kSaveFPRegs,
+                          OMIT_REMEMBERED_SET,
+                          OMIT_SMI_CHECK);
+    }
+  }
+
   // Do the store.
   Register write_register = object;
   if (!access.IsInobject()) {