[llvm] Add executed MC/DC TestVectors to `llvm-cov export` (PR #159119)

[via llvm-commits]

kuzmich321 wrote:

> Thank you, @kuzmich321. Is it your intention to take over the contribution from @Swatinem?

Thanks! Yes, it is. We agreed on that

https://github.com/llvm/llvm-project/pull/159119