Allow Ref instantiate to accept constructor args

[Repiteo]

Expands functionality of Ref instantiate function by adding a variable arguments parameter. In isolation, this doesn't affect existing functionality, but moving forward this will let that function accept constructor arguments for whatever class is being instantiated. This will give all forms of construction the same single-function convenience that instantiate previously provided for empty constructors. Implemented on one file as a proof-of-concept, with potential for a repo-wide sweep down the road.

[akien-mga]

Thanks!