ensure the wrap stack is unique for overrides and decorators

[AndreLouisIssa]

on some lua versions (e.g. lua 5.2) if two functions have the same bytecode, they get assigned the same function object in lua, so the reverse lookup approach of modutil may fail.

to fix this each user-provided function can be (uselessly) wrapped in another function and tail-returned, but this useless wrapper will be the result of the override/decorator operation and used as the reverse lookup rather than the user-provided function.

wraps are immune to this issue since they necessarily get wrapped up in this way already.

[AndreLouisIssa]

there is a problem with this if the value is a table rather than a function, which has so far been supported but never utilised in the wild. meaning either this bug can only be fixed for functions, using special handling, or non-functions become unsupported for overrides and decorators. either way fixing this could be a breaking change as the reference integrity of the output changes.

[AndreLouisIssa]

instead of fixing it, it could be a noted behaviour, and 'uselessly wrapping' your own override/decorated value is a thing users can opt to do, and in the case of tables they can choose the way to do that which makes sense to them (e.g is it a full proxy for the same underlying data?)

[AndreLouisIssa]

I could add another function which does the 'useless wrapping' but keeping the old functions intact, such as the return of OverrideFunction?