[Bug target/86891] [9 Regression] __builtin_sub_overflow incorrect for unsigned types

[wilco at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86891

--- Comment #10 from Wilco <wilco at gcc dot gnu.org> ---
(In reply to Richard Earnshaw from comment #9)
> Fixed.

Yes looking at git blame all of the addv/subv support was added for GCC9, so no
backporting is needed.