Integrate changes #9244,9247,9250 from maintperl into mainline.

Integrate changes #9244,9247,9250 from maintperl into mainline.

Dynaloading in 64-bit AIX with vac.

p4raw-link: @9250 on //depot/maint-5.6/perl: cbdca039b5e144d1778a3f526024bb6da2a58a72
p4raw-link: @9247 on //depot/maint-5.6/perl: 1d70f4d9891a32fb9ebe5b896f754b8c759ffece
p4raw-link: @9244 on //depot/maint-5.6/perl: f816f13eaa91bfe02a64ccda4a80eee889237c24

p4raw-id: //depot/perl@9251
p4raw-integrated: from //depot/maint-5.6/perl@9243 'copy in'
	ext/DynaLoader/hints/aix.pl (@5902..) ext/DynaLoader/dl_aix.xs
	(@9247..) 'merge in' hints/aix.sh (@8537..)