[clang] [Clang][Driver][NFC] Capture -foffload-lto Arg before dereferencing (PR #181752)

[Alexey Bader via cfe-commits]

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

LGTM, but I'd like @jhuber6 to take a look as well.

https://github.com/llvm/llvm-project/pull/181752