[clang] [clang][modules-driver] Add dependency scan and dependency graph (PR #152770)

[Chuanqi Xu via cfe-commits]

ChuanqiXu9 wrote:

> and this line of PRs to add dependency scanning to the clang driver was the main blocker for CMake C++ module support.

I didn't follow this. CMake already supports C++ modules. And I lack an interesting for this since I feel the feature is majorly used for using modules without a build system. But this is only common tutorial in my mind. @naveen-seth would you clarify

> If we lack active maintainers willing to review modules patches, I just want to throw out the idea that we should empower @naveen-seth to be the new C++ module maintainer.

I don't mind this. In my mind, the more maintainer, the better.

https://github.com/llvm/llvm-project/pull/152770