Optimized MiMCSponge Hash Function

This is an optimized version of MiMC Sponge Hash Function.

Version	Creation code size	Creation gas cost	Runtime code size	Runtime gas cost
Deployed MiMC Sponge	11,047	2,209,326	11,035	17,460
Optimized MiMC Sponge	10,980	2,196,303	10,970	17,379

In summary, in comparison to the deployed version, the optimized version;

• is 67 bytes smaller in creation code size
• costs 13,023 gas lesser when deploying
• is 65 bytes smaller in runtime code size
• costs 81 gas lesser when calling