cmd/go/internal/script: check lack of error for non-waiting cmds
In the script engine, if a command does not return a Wait function and
it succeeds, we won't call checkStatus. That means that commands that
don't have a wait function, have a "!" indicating that they are
supposed to fail, and then succeed will spuriously not fail the script
engine test even they were supposed to fail but didn't.
Change-Id: Ic88c3cdd628064d48f14a8a4a2e97cded48890fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/451284 Reviewed-by: Michael Matloob <matloob@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Michael Matloob <matloob@golang.org>