[PATCH] Add BeOS support for libstdc++-v3

[Benjamin Kosnik]

> > I think V3 should honor this switch.
> 
> I believe we do.  There was some discusson about what threading model to
> default to in the absence of a trailing "=foo" to that option.  I patched
> it to default to POSIX since that's the only threading model supported at
> the time.  Alexandre pointed out that, in the absence of specifics, it would
> be better to query the compiler for which model it was using and default
> to that one.  Which is true, but I don't know how to do that right now.

v3 does honor this enable flag. I don't anticipate this part of the patch 
causing problems. I'll look at the rest of it momentarily.

FWIW, the --enable-thread=FOO stuff needs to be standardized, not just 
for libstdc++-v3, but for libjava. Currently, it's hard to correctly sync 
up the compiler and various target libraries with the exact same 
threading model: this needs to change. This plus the concerns that David 
E has about the IBM threading approach means that this top-level 
configure hacking should happen sooner, rather than later.

I'll try to look at it later this week.

-benjamin