This is the first in a series of changes to batch file changes. First,
we have to support invalidating a snaphot with multiple files.
Updates golang/go#31553
Change-Id: I7cd83d9280e3274549a72393bb9010c47eb5dd1e
Reviewed-on: https://go-review.googlesource.com/c/tools/+/215902
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>