[clang] [clang][docs] Add docs for CCC_OVERRIDE_OPTIONS. (PR #142396)

[Abid Qadeer via cfe-commits]

abidh wrote:

The CI failure seems to be for a separate issue. I have opened https://github.com/llvm/llvm-project/pull/142387 for it.

https://github.com/llvm/llvm-project/pull/142396