Improve performance of cbmc's implementation of the gcc integer overflow primitives

[danpoe]

See #4701 for potential ways of improving the performance.

Tracked internally as ADA-563.

[hannes-steffenhagen-diffblue]

@danielsn Could you elaborate on your comment here? I.e. if you have some examples where these checks are causing problems, could you link to a couple here so we have something to benchmark against?

[hannes-steffenhagen-diffblue]

This is internally tracked as ADA-563

[feliperodri]

@danielsn @hannes-steffenhagen-diffblue any updates on this issue? Should we close it?

[jimgrundy]

Dropped to low priority following discussion with @danielsn