i see glibc has a _symbol_ for arch_prctl(), but there's nothing in the headers? a variety of projects seem to `extern` it themselves so they can use the glibc symbol, even though the man page denies that it exists and suggests you use syscall() instead. is this half-existence deliberate, or should it be fixed one way or the other (adding the header declaration or removing the symbol)? i notice musl is the same, but i assume that's just for glibc compatibility rather than an actual decision on their part. before i copy the same oddity in bionic for https://blog.chromium.org/2024/06/building-faster-smarter-chromebook.html i thought i'd at least _ask_ :-)
