cmd/internal/obj: remove dead func Copyp

Change-Id: Iaeb7bcbcdbc46c0e0e40b0aa070c706e0ca53013
Reviewed-on: https://go-review.googlesource.com/39555
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/internal/obj/ld.go

@@ -76,12 +76,6 @@ func mkfwd(sym *LSym) {
 	}
 }
 
-func Copyp(ctxt *Link, q *Prog) *Prog {
-	p := ctxt.NewProg()
-	*p = *q
-	return p
-}
-
 func Appendp(ctxt *Link, q *Prog) *Prog {
 	p := ctxt.NewProg()
 	p.Link = q.Link