Add notes for proper NaN handling in vmin/vmax.
armjit: Correct disabled vslt NaN handling.

Can possibly enable?
armjit: Fix D-prefix sat clamp NAN handling.

They should leave NAN alone.
x86jit: Correctly handle NaNs in vfpxd sat clamps.

May be a small performance jit, but we've seen games with bugs because of
NaNs recently, so better to be safe.
x86jit: Correct vsat0/vsat1 handling.
Merge pull request #6092 from unknownbrackets/armjit-minor

Clean up some NaN handling in some instructions