go/types: implement copy for generic argument types
This is a port of CL 354432 from types2 to go/types
with minor adjustments:
- an error message has a different position
- the constraint literals are wrapped in interfaces
because the interface-free notation has not been
ported yet
Change-Id: I167094b57b39027566f2b7ce3aa97a071bae4da5
Reviewed-on: https://go-review.googlesource.com/c/go/+/354489
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>