Treat a job suspended when any of its component processes is suspended

[magicant]

POSIX says the shell should treat a job as suspended when any child process comprising the job is suspended:

If a process that the shell is waiting for is part of a foreground job that was started as a foreground job and is stopped by a catchable signal (SIGTSTP, SIGTTIN, or SIGTTOU):

• If the currently executing AND-OR list within the list comprising the foreground job consists of a single pipeline in which all of the commands are simple commands, the shell shall either create a suspended job consisting of at least that AND-OR list and the remaining (if any) AND-OR lists in the same list, or create a suspended job consisting of just that AND-OR list and discard the remaining (if any) AND-OR lists in the same list.
• Otherwise, the shell shall create a suspended job consisting of a set of commands, from within the list comprising the foreground job, that is unspecified except that the set shall include at least the pipeline to which the stopped process belongs. Commands in the foreground job that have not already completed and are not included in the suspended job shall be discarded.

Currently, yash waits for all the child processes to suspend, which is different from what is required as above.