Implementation comparison: `crypto_hash/mgrostl256`

Operation	`crypto_hash`
Primitive	`mgrostl256`
Description	Modified Groestl with 256-bit output
Designers	Dhananjoy Dey Gurpreet Kaur SK Pal Vidyavati Nayak
Implementations	`opt-32`	Gurpreet Kaur
	`opt-64`	Gurpreet Kaur
	`ref`	Gurpreet Kaur

Implementation comparison: crypto_hash/mgrostl256