[clang] [Clang] Overflow Idiom Exclusions (PR #100272)

[Vitaly Buka via cfe-commits]

vitalybuka wrote:

> I assume you are going to change fronted to avoid compiler abusing these UBs?

Actually stuff like unsigned overflows are not UB.

Maybe instead of  `-fno-sanitize-overflow-idioms` we convert into
`unsigned-integer-overflow`  into ` check group` so user can -fno-sanitize=<special-case-of>-unsigned-integer-overflow


https://github.com/llvm/llvm-project/pull/100272