Add overflow_assert!

[ojeda]

See https://lore.kernel.org/rust-for-linux/CANiq72=VbcYroRz1EcbzHqFHwaHLewK+DvK756ropM16pDdMuw@mail.gmail.com/

The name mimics other {kind}_assert!s like debug_assert!, as well as core's ub-checks one (assert_unsafe_precondition!).

Please double check if there are already asserts out there (or perhaps even new ones) that could make use of it, and transform (or add) them in a second patch etc.

See #1162 as well.

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[antonio-hickey]

I'll take this on