[clang] [CodeGen] Fix -fsanitize=array-bounds for __sized_by / _or_null pointers (PR #213795)

[Bill Wendling via cfe-commits]

bwendling wrote:

> @bwendling is this ok to land now or do you have more concerns?

Please do! Thanks for the patch.

https://github.com/llvm/llvm-project/pull/213795