Replace HeapType with a non-templated FieldType class.

src/objects-debug.cc

Index: src/objects-debug.cc
diff --git a/src/objects-debug.cc b/src/objects-debug.cc
index b1672c779de6391ec038b67acc92825eba08193c..eb61afec117275a3ebf744d4068ba72a7f862113 100644
--- a/src/objects-debug.cc
+++ b/src/objects-debug.cc
@@ -298,9 +298,9 @@ void JSObject::JSObjectVerify() {
         if (value->IsUninitialized()) continue;
         if (r.IsSmi()) DCHECK(value->IsSmi());
         if (r.IsHeapObject()) DCHECK(value->IsHeapObject());
-        HeapType* field_type = descriptors->GetFieldType(i);
-        bool type_is_none = field_type->Is(HeapType::None());
-        bool type_is_any = HeapType::Any()->Is(field_type);
+        FieldType* field_type = descriptors->GetFieldType(i);
+        bool type_is_none = field_type->IsNone();
+        bool type_is_any = field_type->IsAny();
         if (r.IsNone()) {
           CHECK(type_is_none);
         } else if (!type_is_any && !(type_is_none && r.IsHeapObject())) {