std.posix.kill does not allow signal 0

[psznm]

Zig Version

0.16.0-dev.1424+d3e20e71b

Steps to Reproduce and Observed Behavior

From man 2 kill

If sig is 0, then no signal is sent, but existence and permission checks are still performed; this can be used to check for the existence of a process ID or process group ID that the caller is permitted to signal.

Since zig 0.16 is converting signal to exhaustive enum, the signal 0 is not allowed, so I was unable to migrate a function (without examining kill implementaion and reimplementing with syscall that is used internally)

fn pidIsRunning(pid: std.c.pid_t) !bool {
    const Err = std.posix.KillError;
    std.posix.kill(pid, 0) catch |err| switch (err) {
        Err.PermissionDenied => return true,
        Err.ProcessNotFound => return false,
        Err.Unexpected => return err,
    };
    return true;
}

Expected Behavior

Signal 0 should be allowed in kill to skip sending signal.