base.Errorf("cannot assign %v to %L in multiple assignment%s", src, dst, why)
		return
	}
}

// The result of stringtoruneslit MUST be assigned back to n, e.g.
//
//	n.Left = stringtoruneslit(n.Left)
func stringtoruneslit(n *ir.ConvExpr) ir.Node {
	if n.X.Op() != ir.OLITERAL || n.X.Val().Kind() != constant.String {
		base.Fatalf("stringtoarraylit %v", n)
	}

	// generated code and compiler memory footprint is better without it.
	case ir.OSTR2BYTES:
		// ok

	case ir.OSTR2RUNES:
		if n.X.Op() == ir.OLITERAL {
			return stringtoruneslit(n)
		}

	case ir.OBYTES2STR:
		if t.Elem() != types.ByteType && t.Elem() != types.Types[types.TUINT8] {
			// If t is a slice of a user-defined byte type B (not uint8