go/types: list errors by default in TestManual
go/types: list errors by default in TestManual

This is a port of CL 315729 to go/types, adjusted for the slightly
different test set-up in go/types.

Added a TODO to reconcile these differences.

Change-Id: I71cae712d8fc23b7311ce35e09168b258e07fa35
Reviewed-on: https://go-review.googlesource.com/c/go/+/315850
Trust: Robert Findley <9179eee875d1ee628c37fb47d7e749e855ffd21f@google.com>
Run-TryBot: Robert Findley <9179eee875d1ee628c37fb47d7e749e855ffd21f@google.com>
TryBot-Result: Go Bot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Robert Griesemer <a6752097faebf1f02d80107d77a9be009089afe3@golang.org>

nawawi/go,CAFxX/go,golang/go,golang/go,CAFxX/go,nawawi/go,golang/go,cloudflare/go,CAFxX/go,cloudflare/go,nawawi/go,CAFxX/go,CAFxX/go,nawawi/go,CAFxX/go,nawawi/go,cloudflare/go,golang/go,cloudflare/go,CAFxX/go,cloudflare/go,nawawi/go,golang/go,golang/go,cloudflare/go,cloudflare/go,golang/go,cloudflare/go,CAFxX/go,nawawi/go,nawawi/go,golang/go