[llvm-branch-commits] [llvm] [Coverage] Move SingleByteCoverage out of CountedRegion (PR #110966)

[NAKAMURA Takumi via llvm-branch-commits]

chapuni wrote:

@ellishg I rewrote this based on #120841.
`SingleByteCoverage` is passed to `llvm-cov` via `CoverageData`.

https://github.com/llvm/llvm-project/pull/110966