nif.Likely = true

	// then { s = s[:n] }
	slice := ir.NewSliceExpr(base.Pos, ir.OSLICE, s, nil, newLen, nil)
	slice.SetBounded(true)
	nif.Body = []ir.Node{
		ir.NewAssignStmt(base.Pos, s, slice),
	}

	// else { s = growslice(s.ptr, n, s.cap, a, T) }
	nif.Else = []ir.Node{