Add _AIX_platforms() to provide a workable tag for AIX

[aixtools]

The distutils.util.get_platform() is insufficient for AIX, e.g., it does not provide any idea of bitness.

AIX has, built-in, support for binary compatibility from old to new - so the tag needs to include sufficient detail to know if a potential package is older, the same, or newer than the current running environment.

The proposed tag is:
"AIX-{:04d}-{:04d}-{:2d}".format(vrtl,builddate,bitsize)

where vrtl is the Version,Release,Technology_Level; builddate is the AIX builddate of bos.mp64, and bitsize is 32 if sys.maxsize == 2147483647

[chrahunt]

Related to pypa/pip#6922.

[pradyunsg]

Yet Another Repository

Yea, that's the problem packaging.tags is meant to solve. Until the related tooling adopts it though, it is YAR, as you point out.

p.s. - will this also be used by pypa/wheel - to replaec the pep425tags support there?

Yes. packaging.tags is the intended replacement for pep425tags.py files in all these projects.

[pradyunsg]

There's a broader discussion happening about this at pypa/pip#6922 (comment).