Merkle trees: improvements to proof of mt_retract_to_.
Merkle trees: improvements to proof of mt_retract_to_.

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