compiler: add a newline to function receiver type's debug dump

Change-Id: If54053b2396c5f6cfe11a3cec6d861c7840c07a2
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/168408
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
1 file changed