Introduce HObjectAccess, which is used by LoadNamedField and StoreNamedField to denote what parts

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index 719acb3b39e3f93ebe3139efc841cf5317d6cdaf..fa7457985cc817719be1e25ccb688a873ae05ad0 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -369,8 +369,7 @@ void LAccessArgumentsAt::PrintDataTo(StringStream* stream) {
 
 void LStoreNamedField::PrintDataTo(StringStream* stream) {
   object()->PrintTo(stream);
-  stream->Add(".");
-  stream->Add(*String::cast(*name())->ToCString());
+  hydrogen()->access().PrintTo(stream);
   stream->Add(" <- ");
   value()->PrintTo(stream);
 }