cmd: update vendored golang.org/x/tools for loopclosure improvements
Updates vet to report errors where a loop variable escapes the current
loop iteration by a call to testing.T.Run where the subtest body invokes
t.Parallel().
Change-Id: I727f01d0cdd479ff1b5b1e4f1872c530bfefb263
Reviewed-on: https://go-review.googlesource.com/c/go/+/450435
Run-TryBot: Tim King <taking@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>