cmd/dist: skip testing packages without tests in short test mode
For short all.bash, we can keep the small speedup of 2-10 seconds by
skipping 'go test' on packages without tests. This is viable without
coverage loss since the Go release process is guaranteed to run long
tests for all first class ports.
For golang/go#60463.
Change-Id: Ib5a6bd357d757141bc8f1c1dec148a6565726587
Reviewed-on: https://go-review.googlesource.com/c/go/+/503115
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>