restore pre- and post-conditions in Lib.PQ.Buffer
restore pre- and post-conditions in Lib.PQ.Buffer

mitls/hacl-star,mitls/hacl-star,mitls/hacl-star,mitls/hacl-star,mitls/hacl-star,mitls/hacl-star,mitls/hacl-star,mitls/hacl-star,mitls/hacl-star