internal/ops: hide Ops methods by converting them to package functions

Ops is in the internal package ops, but external clients can reach its
method through op.Ops.Internal. Hide them by converting them to internal
package functions.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

internal/ops/reader.go

@@ -60,7 +60,7 @@ func (r *Reader) Reset(ops *Ops) {
 // ResetAt is like Reset, except it starts reading from pc.
 func (r *Reader) ResetAt(ops *Ops, pc PC) {
 	r.stack = r.stack[:0]
-	r.deferOps.Reset()
+	Reset(&r.deferOps)
 	r.deferDone = false
 	r.pc = pc
 	r.ops = ops
@@ -120,7 +120,7 @@ func (r *Reader) Decode() (EncodedOp, bool) {
 				if t.NumRefs() != 1 {
 					panic("internal error: unexpected number of macro refs")
 				}
-				deferData := r.deferOps.Write1(t.Size(), refs[0])
+				deferData := Write1(&r.deferOps, t.Size(), refs[0])
 				copy(deferData, data)
 				r.pc.data += n
 				r.pc.refs += nrefs