Ensure that formal parameter Names are correctly copied and marked
with the correct Curfn. We need to ensure this even when the underlying
closure has no type parameters.
(Aside: it is strange that the types of things contain formal
parameter names that need to be copied. Maybe that's an underlying
larger problem that needs to be fixed.)
Fixes#45738
Change-Id: Ia13d69eea992ff7080bd44065115bc52eb624e73
Reviewed-on: https://go-review.googlesource.com/c/go/+/313652
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
