`hash_2to1` Miden stdlib binding

The 16 params leave no space on the stack for the pointer for the return value.
Ideally, we should change the MASM signature.

> For `hash_2to1` we could probably write a wrapper procedure that first saves the values to memory and then invokes the procedure using memory pointers. This is how it works for the `keccak256` module - we have a single `hash_memory` procedure which is being called from both `hash_2to1` and `hash_1to1` procedures.

Until then as a temporary workaround we can do a MASM intrinsic.