Change Details

* Add support for (signed) __int128 * Compile-time check assumptions on integer types This is a backport of secp256k1 PR798

* Add support for (signed) __int128 * Compile-time check assumptions on integer types This is a backport of secp256k1 [[https://github.com/bitcoin-core/secp256k1/pull/798 | PR798]]

* Add support for (signed) __int128 * Compile-time check assumptions on integer types This is a backport of secp256k1 [[https://github.com/bitcoin-core/secp256k1/pull/798 | PR798]]