go/types: remove TODO in testdata/examples/types.go

go/types: remove TODO in testdata/examples/types.go

Follow-up on CL 424674. With this change, the files in
testdata/examples are identical to the corresponding
files for types2.

For #54511.

Change-Id: Ic61c089bbf61492094e31057ad2635803f50a30d
Reviewed-on: https://go-review.googlesource.com/c/go/+/424714
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Run-TryBot: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>