CopyFS stipulates the permissions of the created files,
we should test them in the unit test.
* chmod x for testdata/x to test CopyFS for executable
* check the files permissions to ensure CopyFS follows the stipulated
convention
Change-Id: Id13a8ad920ad0c1ff4b801dec3bfa6869cb3101f
Reviewed-on: https://go-review.googlesource.com/c/go/+/616615
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com>