More type annotation for Curve25519
More type annotation for Curve25519

F* was crashing with './Spec.Curve25519.fst(33,2-34,56): (Error) Bound variables 'k#717166' escapes; add a type annotation'

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