[dev.typeparams] test: enable more errorcheck tests
These newly enabled (not anymore excluded) tests pass now
that we run in -G=3 mode when using the new types2 based
noder.
Change-Id: I5e7304c8020f394b79737d67c750bebbe02bd502
Reviewed-on: https://go-review.googlesource.com/c/go/+/289109
Trust: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Dan Scales <danscales@google.com>