Don't use a named pointer type as a receiver type. The

current spec forbids it:
    The type specified by the type name is called ``receiver
    base type''.  The receiver base type must be a type
    declared in the current file, and it must not be a pointer
    type.

R=r
DELTA=2  (0 added, 0 deleted, 2 changed)
OCL=18527
CL=18541

test/chan/powser1.go

@@ -19,13 +19,13 @@ type rat struct  {
 
 type item *rat;
 
-func (u item) pr(){
+func (u *rat) pr(){
 	if u.den==1 { print(u.num) }
 	else { print(u.num, "/", u.den) }
 	print(" ")
 }
 
-func (u item) eq(c item) bool {
+func (u *rat) eq(c item) bool {
 	return u.num == c.num && u.den == c.den
 }