[release-branch.go1.20] crypto/x509: properly gate test on macos version
Fixes the gating of TestIssue51759 by shelling out to sw_vers to check
what version of macOS we are on.
For #64677
Fixes #65379
Change-Id: I5eef4fa39e5449e7b2aa73864625c3abf002aef8
Reviewed-on: https://go-review.googlesource.com/c/go/+/549195
Reviewed-by: Bryan Mills <bcmills@google.com>
Auto-Submit: Roland Shoemaker <roland@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
(cherry picked from commit
400e24a8be852e7b20eb4af1999b28c20bb4ea21)
Reviewed-on: https://go-review.googlesource.com/c/go/+/559516
Auto-Submit: Michael Pratt <mpratt@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>