sync: use atomic.Uint32 in Once
Change-Id: If9089f8afd78de3e62cd575f642ff96ab69e2099
GitHub-Last-Rev:
14165018d67e84685dcf84be0320623ccb3afc0e
GitHub-Pull-Request: golang/go#63386
Reviewed-on: https://go-review.googlesource.com/c/go/+/532895
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Jorropo <jorropo.pgm@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>