Fwd: non-ifunc pt-vfork

[Roland McGrath]

> +/* WARNING: If the compiler cannot turn this into a tail call,
> +   then this mechanism will fail.  The parent will save a return
> +   address on the stack which will be clobbered by the child.  */

Good point.  That should have occurred to me.

> or to remove the non-ifunc portion of this file entirely.  It does seem like
> this sort of thing is going to have to be decided on a host-by-host basis,
> and at least unavailable ifunc will error out at compile-time.

That would be fine with me.

> Alternately, we could drop this tail call stuff and just include vfork.os in
> libpthread.so.  It's not like it's a gigantic object file...

Any individual machine is free to do that.