[clang-tools-extra] [clangd][modules] Discover opened module files outside the compilation database (PR #218958)

[Berkay Sahin via cfe-commits]

berkaysahiin wrote:

> Thanks for the patch!
> 
> If memory serves, there is an issue with problem discussion which this PR addresses. If so, can you please add a reference to this issue into PR description?

Updated the description.

https://github.com/llvm/llvm-project/pull/218958