It affects __FILE__ (C99) __BASE_FILE__ (GNU extension) and __FILE_NAME__ (clang extension).
Should such change be committed directly to the release/10.x branch by @hans ?
Peter can commit to release/10.x himself, or let me know if he prefers me to do it. Thanks for writing release notes!
Updated the comment based on @MaskRay's feedback, thanks!
This (and the previous) patch were based on release/10.x, I plan to commit it later today since the final tag is tomorrow.