cmd/internal/script/scripttest: use GOHOSTARCH to find tool directory
Fixes #72800
Change-Id: Idde7eae13d1c0098e5314935cf8ca823cbc7a7cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/656855
Auto-Submit: Ian Lance Taylor <iant@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Keith Randall <khr@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>