Fixed Object's metaclass. Fixes #3874

Author: Ary Borenszweig

spec/compiler/semantic/reflection_spec.cr

@@ -2,7 +2,7 @@ require "../../spec_helper"
 
 describe "Semantic: reflection" do
   it "types Object class" do
-    assert_type("Object") { types["Class"] }
+    assert_type("Object") { types["Object"].metaclass }
   end
 
   it "types Class class" do

src/compiler/crystal/program.cr

@@ -175,7 +175,6 @@ module Crystal
       string.declare_instance_var("@c", uint8)
 
       types["Class"] = klass = @class = MetaclassType.new(self, object, value, "Class")
-      object.metaclass = klass
       klass.metaclass = klass
       klass.allowed_in_generics = false