[llvm] [IRBuilder] Handle byte types in CreateBitPreservingCastChain (PR #209557)

[Anshil Gandhi via llvm-commits]

gandhi56 wrote:

Thanks for the approval, the failures before rebasing are unrelated to this PR. I enabled auto-merge, hoping that the assertion failure in clang::Sema has been dealt with.

https://github.com/llvm/llvm-project/pull/209557