This change switches from using testenv.Command to
testenv.CommandContext which is a little bit friendlier. It also
switches away from using 'go run' to 'go build' and running the
resulting binary explicitly. This helps eliminate any questions about
signal handling and propagation.
For #72740.
Change-Id: Ife8010da89a7bc439e061fe0c9c6b1f5620d90f1
Reviewed-on: https://go-review.googlesource.com/c/go/+/680977 Reviewed-by: Carlos Amedee <carlos@golang.org>
TryBot-Bypass: Michael Knyszek <mknyszek@google.com>