l2 := typecheck.Conv(n.Args[1].(*ir.MakeExpr).Len, types.Types[types.TINT])
	l2 = typecheck.Expr(l2)
	n.Args[1] = l2 // walkAppendArgs expects l2 in n.List.Second().

	walkAppendArgs(n, init)

	l1 := n.Args[0]
	l2 = n.Args[1] // re-read l2, as it may have been updated by walkAppendArgs

	var nodes []ir.Node

	// if l2 >= 0 (likely happens), do nothing