[pypy-dev] Bump DARWIN_VERSION_MIN to 10.7?

[Jeremy Thurgood]

Hi,

I recently tried to build RevDB on OS X and the build failed because
__thread isn't supported on OS X 10.6 which RPython specifies as the
minimum supported version.

I've updated DARWIN_VERSION_MIN to 10.7 in the reverse-debugger
branch[1], because otherwise it doesn't build at all on OS X. Armin
suggested that there would be a performance benefit to increasing
DARWIN_VERSION_MIN for pypy as well (along with adding darwin to the
SUPPORT__THREAD list). I would like to make this change, but I don't
want to break pypy for anyone who may still need OS X 10.6 support.

As far as I can tell, OS X 10.6 is unsupported (last release in 2011)
but still available as a necessary upgrade step from older versions
that don't support the app store to newer versions that are only
available through the app store. I also have an old laptop running OS
X 10.8, and several applications (including Chrome) have dropped
support for that recently.

[1] https://bitbucket.org/pypy/pypy/commits/a740348ea339c358601d9029bc6811f56c4d71ff

Thanks,
--jerith