Update the comments about the list of Unix systems after CL 601357,
which moved one copy and eliminated another.
Change-Id: I12f5b14a53ce6f8b3a41c9a10f947465c291e2b6
Reviewed-on: https://go-review.googlesource.com/c/go/+/623035 Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Commit-Queue: Ian Lance Taylor <iant@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>