[libc-commits] [libc] [libc] Reject unsupported flags in fchmodat with ENOTSUP (PR #223165)

[Pavel Labath via libc-commits]

labath wrote:

> CC @labath @vonosmas - If you have a moment, I'd appreciate any feedback on this fix for `fchmodat`'s syscall wrapper and flag handling.

This patch isn't wrong, but it would kind of have to be reverted when we add support for SYS_fchmodat2 (which I'd implement as adding the argument back to the syscall wrapper, and then checking of zero in the `#ifndef SYS_fchmodat2` branch). 

Would you be willing to add support for fchmodat2 instead?

If not, let me know, and I'll merge this.

https://github.com/llvm/llvm-project/pull/223165