v2.1.x: Open BSD 6.0 and patcher problems

[jsquyres]

Filing a duplicate issue to #2049 for v2.1.0 (it's a blocker on v2.0.2, so it needs to be a blocker on v2.1.0, too).

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As reported by Paul H., Open BSD 6.0 disallows the patcher code's mprotect call.

See https://mail-archive.com/devel@lists.open-mpi.org/msg19527.html

[hppritcha]

@hjelmn could you get this working on v2.x?

[hppritcha]

Waiting on #2107 to get merged in to master.

[jsquyres]

Per discussion on the 2017-02-21 webex, @hjelmn said he would try to get this in today.

[hppritcha]

@jsquyres should we push this to 2.1.1?