[release-branch.go1.13] os: skip TestPipeThreads on GOOS=darwin
Updates #32326.
Updates #33953.
Change-Id: I97a1cbe682becfe9592e19294d4d94f5e5b16c21
Reviewed-on: https://go-review.googlesource.com/c/go/+/192342
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
(cherry picked from commit
bac5b3f0fe7838ecf6e206fa8d2123c7771eb976)
Reviewed-on: https://go-review.googlesource.com/c/go/+/192757
Run-TryBot: Andrew Bonventre <andybons@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>