AIX atomicity.h support

[David Edelsohn]

	The patch works for as much as it is trying to accomplish.  The
larger problem is that the libtool support for AIX has a lot of
misconceptions and the v3 configuration mechanism is far too SVR4-,
Solaris-, and Linux-centric.  v3 needs to learn how to deal with AIX
atomicity, AIX pthreads, and AIX shared libraries.

	I still have not heard any response to my request from last May
for help with the configuration issues.  I can help explain AIX functional
equivalence to Linux, but this effort needs more attention from people who
understand libtool and v3/configure so that v3 uses the appropriate files
and defines the appropriate macros.  AIX 4.3.3 support is part of the
gcc-3.0 release criteria, so the lack of assistance is going to delay
everyone.

David
===============================================================================
David Edelsohn                                      T.J. Watson Research Center
dje@watson.ibm.com                                  P.O. Box 218
+1 914 945 4364 (TL 862)                            Yorktown Heights, NY 10598