[clang] [compiler-rt] [ubsan] Display correct runtime messages for negative _BitInt (PR #96240)

[via cfe-commits]

earnol wrote:

How i can see the full amount of breakage on different platforms proactively?
I have created a PR: https://github.com/llvm/llvm-project/pull/104607 to address the big endian issue with the test as my // REQUIRES: x86-registered-target turned out not to be enough to exclude running test in the big endian platforms.

https://github.com/llvm/llvm-project/pull/96240