[clang] Sanitizer: Support -fwrapv with -fsanitize=signed-integer-overflow (PR #82432)

[Nikita Popov via cfe-commits]

nikic wrote:

Shouldn't plain `-fsanitize=undefined` disable this sanitizer by default (requiring explicit opt-in)? In `-fwrapv` mode this is not undefined behavior, so `-fsanitize=undefined`  should not complain about it.

https://github.com/llvm/llvm-project/pull/82432