Refactor vfs lookup into 'func stat', which knows the internal
data structures for the vfs and returns information about a
given path. The callers can then all use stat and avoid direct
knowledge of the internal data structures.
This is setting up for a different internal data structure.
Change-Id: I496b7b3fb686cdde81b14687f65eb0bf51ec62be
Reviewed-on: https://go-review.googlesource.com/c/go/+/628699
Auto-Submit: Russ Cox <rsc@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Matloob <matloob@golang.org>