Use Func* instead of Class* for minstr C++ helpers

Use Func* instead of Class* for minstr C++ helpers

Summary:
Instead of using Class* to pass the context, pass the function pointer. Then pass the modulename through the function pointer.

This allows us to check modules correctly in the next diff when using these helpers.

https://our.intern.facebook.com/intern/servicelab/1401288388/
https://our.intern.facebook.com/intern/servicelab/1401288387/
https://our.intern.facebook.com/intern/servicelab/1301288740/
https://our.intern.facebook.com/intern/servicelab/1401288389/
https://our.intern.facebook.com/intern/servicelab/1501288469/
https://our.intern.facebook.com/intern/servicelab/1101287071/
https://our.intern.facebook.com/intern/servicelab/1501288471/
https://our.intern.facebook.com/intern/servicelab/1501288470/

Reviewed By: oulgen

Differential Revision: D39033444

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