More AIX DSO tweaking. Apache's AIX DSO emulation code does not work with

64 bit builds of Apache. Use native DSO support with AIX V4.3 and later.
Native AIX DSO support is broken prior to 4.3, so we need to continue
using Apache's version on pre 4.3 releases of AIX
PR: 5309
Submitted by: Chris Graham (chrisg@webwombat.com.au)
Reviewed by: Bill Stoddard


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@84267 13f79535-47bb-0310-9956-ffa450edef68