Make HConstant::InstanceOf less ambiguous.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index a4c54e761e731944247005f0b940df7804617206..2d2131f3eee27aa599fb5aa5866c345b36890182 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -2866,7 +2866,7 @@ HCheckMaps* HCheckMaps::New(Zone* zone,
   check_map->Add(map, zone);
   if (map->CanOmitMapChecks() &&
       value->IsConstant() &&
-      HConstant::cast(value)->InstanceOf(map)) {
+      HConstant::cast(value)->HasMap(map)) {
     check_map->omit(info);
   }
   return check_map;