[clang] [cmake] Add LLVM_FORCE_VC_REVISION option (PR #67125)

[Tobias Hieta via cfe-commits]

https://github.com/tru commented:

It looks fine to me, but maybe we should have an entry for it in the `CMake.rst` documentation since the other `LLVM_*_VC` options are documented.

https://github.com/llvm/llvm-project/pull/67125