The patch speaks for itself.

PROBLEMS

@@ -89,3 +89,12 @@ failures in other parts of the code.
 (See Ticket #426.)
 
 Workaround: modify the target to +O2 when building with no-asm.
+
+* Poor support for AIX shared builds.
+
+do_aix-shared rule is not flexible enough to parameterize through a
+config-line. './Configure aix43-cc shared' is working, but not
+'./Configure aix64-gcc shared'. In latter case make fails to create shared
+libraries. It's possible to build 64-bit shared libraries by running
+'env OBJECT_MODE=64 make', but we need more elegant solution. Preferably one
+supporting even gcc shared builds. See RT#463 for background information.