path/filepath, io/fs: add SkipAll

path/filepath, io/fs: add SkipAll

Fixes #47209

Change-Id: If75b0dd38f2c30a23517205d80c7a6683a5c921c
Reviewed-on: https://go-review.googlesource.com/c/go/+/363814
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Bryan Mills <bcmills@google.com>