[clang] [llvm] [Clang][CodeGen][X86] Fix crash on __int128 bit-field access units (PR #216777)

[Andrzej Warzyński via cfe-commits]

banach-space wrote:

> At the moment, we're not proposing/insisting on anything like this (though we are close to making it built-by-default(via RFC) which will cause lit test failures to hit CI).

Once there is at least one buildbot with ClangIR enabled, people will start receiving notifications on their PRs (from post-commit CI). We should probably sent an RFC soon.

https://github.com/llvm/llvm-project/pull/216777