[dev.typeparams] reflect: use goarch.PtrSize instead of the duplicated ptrSize [generated]

[git-generate]
cd src/reflect
gofmt -w -r "PtrSize -> goarch.PtrSize" .
gofmt -w -r "ptrSize -> goarch.PtrSize" .
goimports -w *.go

Change-Id: Ib534bb0ecde10d93f45365ab4f8efd620d6d2ef3
Reviewed-on: https://go-review.googlesource.com/c/go/+/328346


Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>