[i386] BMI1 assembly version of MD5Transform added to hash package

Summary

This merge request adds the BMI1 implementation of MD5Transform from !497 (merged) converted for i386.

What is the current bug behavior?

N/A

What is the behavior after applying this patch?

When compiling for a processor that supports BMI1, the MD5 hash should see a performance gain over the vanilla i386 version due to heavy use of ANDN.

Relevant logs and/or screenshots

See !497 (merged) for more information.

Additional notes

While the regular assembly implementation has been modified, only spacing and capitalisation are affected and the actual instructions are unchanged.