Report thread stack size bugfix for AIX.

doc/PLATFORMS/AIX.txt

@@ -7,3 +7,14 @@ from Thiebaut Champenier
   dirs in <Zope-build>/python/lib that contain .c files... and it
   worked just great. But I'm sure it's not the best solution
 
+from Wolfgang Roesner (reporting segfaults and a fix)
+
+  The default stack size for a pthread on AIX (at least in my
+  configuration) is 96kB. On Solaris it's 1M. As soon as I explicitly
+  set the initial stack size to 1M the problem went away and it
+  appears as if Zope is up and running.
+
+  Unfortunately I really had to change "thread_pthread.h" in Python
+  which obviously is not a nice thing to do as I now have a need for
+  my own private version of Python. But at least I have a running
+  version of Zope on AIX.