[ic] Load IC data handlers now support prototype chain checks with global and dictionary objects.

src/ic/x64/handler-compiler-x64.cc

Index: src/ic/x64/handler-compiler-x64.cc
diff --git a/src/ic/x64/handler-compiler-x64.cc b/src/ic/x64/handler-compiler-x64.cc
index ef4f411656fc55604db243195b96f39cfdb48c66..8e41df24b42b2a533f87fca449b06398c8876957 100644
--- a/src/ic/x64/handler-compiler-x64.cc
+++ b/src/ic/x64/handler-compiler-x64.cc
@@ -475,10 +475,7 @@ Register PropertyHandlerCompiler::CheckPrototypes(
                                 name, scratch2, miss);
     } else if (current_map->is_dictionary_map()) {
       DCHECK(!current_map->IsJSGlobalProxyMap());  // Proxy maps are fast.
-      if (!name->IsUniqueName()) {
-        DCHECK(name->IsString());
-        name = factory()->InternalizeString(Handle<String>::cast(name));
-      }
+      DCHECK(name->IsUniqueName());
       DCHECK(current.is_null() ||
              current->property_dictionary()->FindEntry(name) ==
                  NameDictionary::kNotFound);