emb := typ.EmbeddedType(i)
		switch emb := emb.(type) {
		case *types.Interface:
			list = append(list, w.sortedEmbeddeds(emb)...)
		case *types.Union:
			var buf bytes.Buffer
			nu := emb.Len()
			for i := 0; i < nu; i++ {
				if i > 0 {
					buf.WriteString(" | ")
				}
				term := emb.Term(i)
				if term.Tilde() {
					buf.WriteByte('~')
				}
				w.writeType(&buf, term.Type())
			}

	for _, call := range f.Calls {
		if call.Done {
			continue
		}
		start := f.offset(call.Call.Pos())
		end := f.offset(call.Call.End())
		str, nu := p.rewriteCall(f, call)
		if str != "" {
			f.Edit.Replace(start, end, str)
			if nu {
				needsUnsafe = true
			}
		}
	}
	return needsUnsafe
}

// rewriteCall rewrites one call to add pointer checks.