[dev.typeparams] cmd/compile: port fix for issue46725 to transform.go

Allow fix for issue46725 to work for -G=3 mode.

Change-Id: Id522fbc2278cf878cb3f95b3205a2122c164ae29
Reviewed-on: https://go-review.googlesource.com/c/go/+/331470


Trust: Dan Scales <danscales@google.com>
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>