dir/inprocess: add a test for whichaccess(directory)
dir/inprocess: add a test for whichaccess(directory)

This test case was not covered.

If you want to list the contents of dir,
look at whether dir/Access grants you list permission.

Change-Id: I0978adb7810c431627d2759d675e17e4bf5dc6bf
Reviewed-on: https://upspin-review.googlesource.com/8022
Reviewed-by: Andrew Gerrand <395a7d33bec8475c9b83b7d440f141bcbd994aa5@golang.org>

upspin/upspin,upspin/upspin