#42515 identified a NetBSD kernel bug (kern/50094) affecting the Go runtime. http://golang.org/cl/277332 introduced a (rather subpar) workaround for this issue.

@jdolecek-zz notes that the fix for this bug is included in NetBSD 9.2, making the workaround unnecessary.

Ideally we just drop http://golang.org/cl/277332, but this depends on our support policy for NetBSD. https://github.com/golang/go/wiki/NetBSD states that we currently support NetBSD 7+, but not what the official policy is. (OTOH, e.g., OpenBSD is explicitly supported only for the two most recent releases: https://github.com/golang/go/wiki/OpenBSD#longterm-support).

Based on my reading of https://www.netbsd.org/releases/formal.html, my interpretation would be that Go should support NetBSD 8 and 9 (and presumably drop 8 when 10 is released?). Do others agree? If so, we should probably add a version check to the workaround and keep it until NetBSD 9 is dropped.

cc @bsiegert @dmitshur @mknyszek