go/doc: whole file is used as example even when there are tests or benchmarks [1.14 backport]

[gopherbot]

@FiloSottile requested issue #38409 to be considered for backport to the next 1.14 minor release.

@gopherbot please open a backport issue for 1.14.

This is a regression that impacts user visible documentations, without a workaround on the doc generation side (as opposed to modifying the target source, which might be an existing version or third-party).

[andybons]

Approved as this is primarily a documentation issue with no workaround (outside of modifying the target source). The change is minimal as well.

[gopherbot]

Change https://golang.org/cl/232868 mentions this issue: [release-branch.go1.14] go/doc: fix detection of whole file examples

[gopherbot]

Closed by merging 14c92c5 to release-branch.go1.14.

[flyingmutant]

Is there an ETA for https://godoc.org and https://pkg.go.dev updating to 1.14.3?