Gentoo is currently including two intrusive Prefix-related patches that are likely to make Gentoo clang incompatible with native clang on the related systems: https://github.com/mgorny/llvm-project/commit/a3dc724f13a84ad6600ce769dc1c0d80f12c210e https://github.com/mgorny/llvm-project/commit/dbdf7ed4d731ad544797bccdfd5b88b52867065b Please engage with upstream to get the prefix-specific issues resolved in a non-intrusive way that could be accepted there.
Please note we also have some hacky changes here: https://github.com/gentoo/gentoo/blob/master/profiles/features/prefix/standalone/profile.bashrc#L31-L43 These are specific to prefix-standalone on Linux.
Given no effort to move forward and the fact that patches stopped applying again, I'm removing them from 16.0.0.9999.
Sorry, it's ok, drop them. We cannot support Clang-toolchain at this point.
