Intrinsics: md5crypt mmxput()

http://www.openwall.com/lists/john-dev/2015/09/05/3

magnum, Jim, Simon, Lei -

Some speedup for md5crypt on CPU might be possible through vectorizing
the mmxput() functions, or through use of SHLD/SHRD instructions
(available since 386) or other archs' equivalents (I think ARM has this
too) in mmxput3() when not vectorized (somehow gcc does not do it for
us). These functions are similar to buf_update() in cryptmd5_kernel.cl,
where I've added uses of amd_bitalign() and NVIDIA's funnel shifter
recently (analogous to SHLD/SHRD), and which obviously is processed on
the SIMD units on GPUs (can do it on CPUs as well, although no SHLD/SHRD
then, unless a given CPU architecture has them in SIMD form as well -
need to look into that).

Alexander