B.4.236. `PMINUB': Packed Unsigned Integer Byte Minimum
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PMINUB mm1,mm2/m64 ; 0F DA /r [KATMAI,MMX]
PMINUB xmm1,xmm2/m128 ; 66 0F DA /r [WILLAMETTE,SSE2]
`PMINUB' compares each pair of bytes in the two source operands, and
for each pair it stores the minimum value in the destination register.