Add an option not to inline a specific CallOp

Hi!

In our project we use the inliner, but we need to leave some CallOps as they are. Meaning we want to control whether a CallOp will be inlined or not.

I saw it was done in the Test dialect, but not in the Func dialect.

I thought of using the Test dialect approach also in the Func dialect. I would like to know if it sounds like a good idea for others as well.

Thanks in advance,
Maya