init_vdso_clock_gettime

fn init_vdso_clock_gettime(clk: clockid_t, ts: *timespec) callconv(.c) usize {
    const ptr: ?VdsoClockGettime = @ptrFromInt(vdso.lookup(VDSO.CGT_VER, VDSO.CGT_SYM));
    // Note that we may not have a VDSO at all, update the stub address anyway
    // so that clock_gettime will fall back on the good old (and slow) syscall
    @atomicStore(?VdsoClockGettime, &vdso_clock_gettime, ptr, .monotonic);
    // Call into the VDSO if available
    if (ptr) |f| return f(clk, ts);
    return @bitCast(-@as(isize, @backingInt(E.NOSYS)));
}