I left a few more comments, but I see that many of my earlier comments (both in Rietveld and main bug thread) still apply.

I’m still struggling to understand all the special cases for the find_library() argument. You seem to have added even more recently (although I think you removed some as well). Can you point to any documentation, command lines, etc demonstrating why Python should support:

find_library("libNAME")
find_library("search:paths/NAME")
find_library("NAME.so*")
find_library("/NAME")  # Not sure if this case is even relevant

Perhaps it would help if you explained what a typical AIX compiler or linker command line looks like. Or if you updated the documentation <https://docs.python.org/3.5/library/ctypes.html#finding-shared-libraries> to explain the cases for AIX.