[clang] [clang][Dependency Scanning] Adding an API to Diagnose Invalid Negative Stat Cache Entries (PR #135703)

[Jan Svoboda via cfe-commits]

jansvoboda11 wrote:

I don't think workers need to be involved at all - we just need to pass the same VFS to this function that we use to instantiate all workers. For example, downstream `clang_experimental_DependencyScannerWorker_create_v0()` always uses `llvm::vfs::createPhysicalFileSystem()`, so I'm thinking whatever C API we invent for this functionality, it can operate on the service only, it just needs to be consistent in using the physical VFS. That C API can return `CXCStringArray` and let the build system invent its own message format.

https://github.com/llvm/llvm-project/pull/135703