base.Errorf("%v can't be allocated in Go; it is incomplete (or unallocatable)", call.Type().Elem())
		}
		var r ir.Node
		switch {
		case isAppendOfMake(call):
			// x = append(y, make([]T, y)...)
			r = extendSlice(call, init)
		case call.IsDDD:
			r = appendSlice(call, init) // also works for append(slice, string).
		default:
			r = walkAppend(call, init, as)
		}
		as.Y = r
		if r.Op() == ir.OAPPEND {