liblzma: SHA-256: Optimize the Maj macro slightly.
liblzma: SHA-256: Optimize the Maj macro slightly.

The Maj macro is used where multiple things are added
together, so making Maj a sum of two expressions allows
some extra freedom for the compiler to schedule the
instructions.

I learned this trick from
<http://www.hackersdelight.org/corres.txt>.

pombreda/go-liblzma,pombreda/go-liblzma,pombreda/go-liblzma