C11 threads ABI questions - enum values

[Roland McGrath]

> Thanks for the feedback. Since then we've got C11 threads support
> committed in musl, with the following definitions. Are these
> acceptable for glibc too? They're the same ones I proposed before.

No guarantees until we actually implement something in glibc.  But they
seem fine to me.  The possible exception is that for interfaces where the
only valid thing is to pass in of the specified enum values, there is
something to be said for none of those values being zero (or -1) so that
applications can't sloppily use literal 0 (or uninitialized statics or the
like) and have it work but be non-portable and nonconforming.