Now that we're no longer special-casing clock usage for MacOS (see #17800), we're not referencing anything defined in these headers.
Incidentally, this removes our last reference to the __MACH__ system def. 🎉
Now that we're no longer special-casing clock usage for MacOS, we're
not referencing anything defined in these headers.
ACK d36146009fb3fc9b9a772823b4df139a85173481 - thanks.
utACK d36146009fb3fc9b9a772823b4df139a85173481