libio build bitching about bits/libc-lock.h

[David Edelsohn]

>>>>> Toon Moene writes:

Toon> there's no file found for <bits/libc-lock.h>.

Toon> Is this an autoconf issue ?  Or did I screw up something installing this
Toon> distribution (of course, I cannot doubt Debian :-)

	You did not screw anything up.  This is a basic compatibility
issue with the current thread-safe support in libstdc++-v3.  If you are
not running GNU libc -- and only the one, true, correct version of GNU
libc -- you are condemned to purgatory :^).

	libstdc++-v3/libio uses the locking primitives of
bits/stdio-lock.h as the abstraction layer for libio which is common with
GNU libc.  Non-GNU systems are going to need to figure out how to
implement this compatibility and the version of GNU libc needs to match
libstdc++-v3 on GNU/Linux.

	This is a portability issue that is unresolved.

David