stl_threads.h cleanups

[Loren James Rittle]

In article <20030611113953.4d8ae4eb.bkoz@redhat.com>,
Benjamin Kosnik<bkoz@redhat.com> writes:

> Large parts of this file appear to be unused, or under-used. For example, 

>   struct _STL_auto_lock

> is completely unused.

>   struct _Refcount_Base

> is used only in ext/rope, and then only if #__GC is not defined. 

> Why is this stuff around, if it's not being used... can any of it be removed?

My best guess is junk of configurations past.  I'd support seeing all
macro-guarded regions resolved (either way) and now unused code axed.
There is also flatting, refactoring possible (e.g. there are still at
least two/three different idioms used to key threading support,
sometimes layered) now that we "know" an external code base will never
be merged again.  I think that was a real issue raised in the past.  I
have no comment on whether that could ever happen again.

Regards,
Loren