runtime: print fatal messages without interleaving
Grab the print lock around the set of prints we use to report
fatal errors. This ensures that each fatal error gets reported
atomically instead of interleaved with other fatal errors.
Fixes #69447
Change-Id: Ib3569f0c8210fd7e19a7d8ef4bc114f07469f317
Reviewed-on: https://go-review.googlesource.com/c/go/+/615655
Auto-Submit: Keith Randall <khr@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>