Workaround for a bug inside `cbindgen`. For some reason it does not like
us exporting constants that depend on other constants that are *not*
defined as a part of the same module.
Init no longer changes the default scheme to initfs at any point in
time. And for sandboxing you would be switching scheme namespace, not
default scheme.
It should be possible to mix and match relibc version from before and
after this change without breaking exec, though I haven't tested it.
`timespec_get` and `timespec_getres` are both C23 functions. They're
similar to the POSIX functions `clock_gettime` and `clock_getres`, but
both sets of functions define extra, exclusive features. I didn't
implement the extra features yet, partially because Redox doesn't seem
to support them yet either.
`posix_fallocate` ensures that a byte range in a file is allocated so
that subsequent writes don't fail. Unlike ftruncate, posix_fallocate
does not shrink files.
The Linux syscall fallocate is similar to posix_fallocate except with
far more control over how byte ranges are allocated (e.g. it supports
file holes and other features). This MR doesn't implement fallocate as
it requires syscall and redoxfs support.
Finally, I changed the flags for flock from usize to c_int. That matches
what we have in libc and also avoids some silly, needless type casting.
Like the other "at" functions, renameat renames files with respect with
a directory descriptor. "renameat2" is Linux specific but really nice -
it adds a flag which supports atomically swapping two files or failing
if the target already exists. The latter is easily supported in relibc.
The former requires redoxfs support.
Besides the impl itself, I refactored "cap_path_at" into what it really
is: a mini openat2-like function.
auronandace