time: timer reset sometimes ignored, causing delayed ticks [1.16 backport]

[gopherbot]

@ianlancetaylor requested issue #47762 to be considered for backport to the next 1.16 minor release.

@gopherbot Please open a backport to 1.16 and 1.17.

This bug can cause timers to fail to fire. It appears to be new in recent 1.16 releases.

[gopherbot]

Change https://golang.org/cl/350000 mentions this issue: [release-branch.go1.16] runtime: in adjustTimers back up as far as necessary

[cagedmantis]

This issue has been approved as it is a major issue without any viable workarounds.

[gopherbot]

Closed by merging 552410f to release-branch.go1.16.