Issue 24839: platform._syscmd_ver raises DeprecationWarning

platform._syscmd_ver() calls platform.popen() which raises a DeprecationWarning. This causes tests with `@skip(platform.machine() == '...')` decorators to fail.

The fix is to call `os.popen()` - patch attached. (platform.popen() just raises the warning and then calls os.popen(), so should be no risk here.)

Larry - since this causes spurious failures in numpy's test suite, can we get it into 3.5?

Yes, I'll accept that for 3.5.0.  Paste a link to a pull request here at your earliest convenience (and opportunity).

Have you opened up the repo yet? I'm getting "no access" errors from BB.

Not yet.  I'll open it after I release 3.5.0rc1.  I'll send email to clp-d and clp-c when I do.  I can email you privately too if you like.

My Bitbucket repo is now public.

https://bitbucket.org/larry/cpython350

New changeset 7cfe20a6395d by Steve Dower in branch '3.5':
Issue #24839: platform._syscmd_ver raises DeprecationWarning
https://hg.python.org/cpython/rev/7cfe20a6395d

PR is at https://bitbucket.org/larry/cpython350/pull-requests/1/issue-24839-platform_syscmd_ver-raises/diff

(For my sanity, your 3.5 branch and the hg.p.o 3.5 branch *are* currently in sync, yes? Any value in adding a 3.5.0 branch for your divergence so we can avoid the need for multiple clones?)

They are currently in sync, yes.  The 3.5 branch has been a ghost town the last day or two, which tbh has been pleasant for me.helpfu

Merged.  Please forward-port to 3.5.1 and 3.6.  Thanks!

(See?  Already I can tell this rc-cycle is going to be way easier on me than 3.4 was.)