[clang] [llvm] [gcov] Add support for -fprofile-abs-path (PR #230077)

[Nicolas Qiu Guichard via cfe-commits]

nicolas-guichard wrote:

The test failure was unrelated (https://github.com/llvm/llvm-project/issues/230069) and should be fixed by the rebase.

I don't know if you want to wait for the code coverage maintainers to take a look at this, but note one of you will have to press the merge button for me.

https://github.com/llvm/llvm-project/pull/230077