[clang] [clang][deps] Add in-flight query caching to `DependencyScanningFilesystemSharedCache` (PR #199680)

[Jan Svoboda via cfe-commits]

https://github.com/jansvoboda11 commented:

This is a great finding and the new approach makes sense conceptually. I think we can improve clarity and performance with some tweaks to the implementation.

https://github.com/llvm/llvm-project/pull/199680