[clang] [Clang][Driver] Skip empty strings in getAArch64MultilibFlags (PR #97827)

[Peter Smith via cfe-commits]

https://github.com/smithp35 approved this pull request.

Thanks for the update LGTM. I've set approved, but please wait for a few days to let other reviewers comment.

https://github.com/llvm/llvm-project/pull/97827