Fixes #11649 Updates #16369 Co-authored-by: James Sanderson <jsanderson@tailscale.com> Change-Id: I63eaa18fe870ddf81d84b949efac4d1b44c3db86 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This is a useful primitive for asynchronous execution of ordered work I want to use in another change. Updates tailscale/corp#16833 Signed-off-by: James Tucker <james@tailscale.com>