[clang] [flang] [clang][driver] Special care for -l flags in config files (PR #117573)

[Sam James via cfe-commits]

https://github.com/thesamesam commented:

This seems OK to me, although I'd feel more comfortable if we had a test which relied on `--Wl,--as-needed`.

https://github.com/llvm/llvm-project/pull/117573