go/types, types2: test that error format strings have matching parentheses/brackets

go/types, types2: test that error format strings have matching parentheses/brackets

Also, for go/types, switch to using syntax.Inspect instead of
(deprecated) syntax.Crawl.

Change-Id: I8333079040e9676e0a61c23d09d41ca790526eeb
Reviewed-on: https://go-review.googlesource.com/c/go/+/460759
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Run-TryBot: Robert Griesemer <gri@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>