Add mechanism to hooks to report "true" source location

[dgollahon]

Macros like the memoize macro from memoizable redefine methods with a small wrapper method. Unfortunately, this confuses mutant and breaks proper insertion. I have several cases of a macro like this and currently have to monkey patch and extend logic like this that mutant already does for Sorbet, etc.. It would be very helpful if there were a public API option for this so I wouldn't have to maintain an awkward patch.