@dmitshur requested issue #57050 to be considered for backport to the next 1.20 minor release.

@gopherbot Please consider this as a backport to Go 1.20 and 1.19.

This is a documentation-only fix to document a Go 1.19 feature added to go test and go generate. It'll be easier for users who wish to rely on it to do so when it's documented, and avoids confusion about it otherwise only appearing in cmd/go documentation in Go 1.21 onwards.
(I'm happy to help with preparing backport CLs if approved.)