Thanks everyone for the input on this issue.  We've had some discussions here at PyCon US and I think the consensus is that we all agree with Nathaniel's comment above that, for 3.6.x, that modules built on 3.6.2 (and later 3.6.x) should be importable on any 3.6.x (including 3.6.0), and 3.6.2 (and later 3.6.x) should be able to import modules built on any 3.6.x.  Steve Dower has suggested that it would be nice to provide a compile option so that users could compile an extension with the benefit of the 3.6.1 fix if they do not have the need for 3.6.0 compatibility.  I think that would be nice but not essential.  But we do need to ensure that 3.6.2 is fixed to be compatible as above prior to 3.6.2rc currently scheduled for 2017-06-26.  Serhiy, is that doable?

Otherwise, I believe no further changes are needed for the other branches, correct?