[PATCH] Improve LinuxThreads compatibility in rfork()

[Petr Salinger]

>> The 1st patch satisfies this. I agree that SIGCHLD part
>> is not easily readable.
> The SIGCHLD part is ugly. This is why I am asking about possible ways
> to overcome this.

We need a way to specify "no signal".
It can be "new flag" or "ugly SIGCHLD".

new flag:
   pros: cleaner design
   cons: one bit of flags eaten
   cons: GNU/kFreeBSD have to detect at runtime which "no signal" have to use
   cons: GNU/kFreeBSD have to add "ugly SIGCHLD" for some time
         (up-to and including next Debian release) anyway

ugly SIGCHLD:
   pros: immediate GNU/kFreeBSD compatibility
   cons: ugly design

But definitely, it would be much, much better to have "new flag" compared 
to diverge indefinitely ;-)

What should be name of the "new flag" ?

#define RFTHPNONE (1<<19)  /* do not send exit notification signal to the parent */

Petr