[clang-tools-extra] [clang-include-cleaner] Fix incorrect directory issue for writing files (PR #111375)

[kadir çetinkaya via cfe-commits]

https://github.com/kadircet commented:

thanks a lot for the revision!

One concern is, we can't really use `getAllCompileCommands()` reliably either, not all compilation databases implement that, and even if they do this is gonna be an overkill. For example for chromium we'll iterate over tens of thousands of compile flags, just to modify a handful of files. I've made some suggestions in line.

Also I think it's easier if we put absolute-paths from CDB into the `EditedFiles` and just remap them to absolute paths per tools working directory afterwards when we can.

https://github.com/llvm/llvm-project/pull/111375