[clang] [clang-cl] Accept `cl`-style output arguments (`/Fo`, `-Fo`) for `--fmodule-output` (PR #121046)

[Sharadh Rajaraman via cfe-commits]

sharadhr wrote:

A quick bump. I'd like to get this reviewed hopefully in time for the Clang 20.x release. I think having it in 19.x is a lost battle, it's a bit too late for that. 

https://github.com/llvm/llvm-project/pull/121046