Remove special handling of fields in combination with elements transitions in Crankshaft.

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 e9210a9eed693843f20246ac7fd9c6ca9424b516..4994d94e36ec2f2ba425ca31eacb02199837d1b8 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -2780,9 +2780,6 @@ static bool CompactEmit(SmallMapList* list,
                         int i,
                         Isolate* isolate) {
   Handle<Map> map = list->at(i);
-  // If the map has ElementsKind transitions, we will generate map checks
-  // for each kind in __ CompareMap(..., ALLOW_ELEMENTS_TRANSITION_MAPS).
-  if (map->HasElementsTransition()) return false;
   LookupResult lookup(isolate);
   map->LookupDescriptor(NULL, *name, &lookup);
   return lookup.IsField() || lookup.IsConstant();