compiler-dependent patch

[Mojca Miklavec]

Hi,

What would be the proper way to only apply a patch if clang < 500 is used?

Python 3.5 contains a configure test that misbehaves with clang 425
(it gives the wrong impression that a feature is supported when it is
not) and leads to a build failure. One option would be to blacklist
clang < 500, but we could just as well apply a trivial patch on clang
< 500 only.

Any ideas?

The relevant bug reports are here:
    http://trac.macports.org/ticket/49272
    https://bugs.python.org/issue24844
If anyone knows a way to check for "atomic" in a more robust way, that
would be even better, but it would be nice to get python35 working.

Mojca