[clang] [clang][deps] Only bypass scanning VFS for the module cache (PR #88800)

[Paul Kirth via cfe-commits]

ilovepi wrote:

hmm, it does weirdly seem to be working now. Thanks for taking a look.  

@mysterymath you're about the only person I know w/ much knowledge about debuginfod testing, can you take a look when you get time? It seems like this could be a flake. If it turns out to be, lets file an issue and continue discussion there.

https://github.com/llvm/llvm-project/pull/88800