BUILD: adjust makefile for AIX 5.1

AIX 5.1 has trouble with ss_family which is __ss_family there.
Just remap it in the makefile and provide a new target.
BUG/MEDIUM: pattern: fix wrong definition of the pat_prune_fcts array

Commit 6f7203d ("MEDIUM: pattern: add prune function") introduced an
array of functions pat_prune_fcts[] but unfortunately declared it in
pattern.h without marking it "extern", resulting in each file including
it having its own copy.
CLEANUP: pattern: move array definitions to proto/ and not types/

All symbol definitions should be in proto/ and not types/.