Change condition to opposite if lhs is constant

Swap operands if lhs is constant. Handeled unsigned comparison
in insruction simplifier. Fixed NaN comparison: no matter what
bias is set result of Equal and NotEqual operations should not
depend on it. Added checker tests.

Change-Id: I5a9ac25fb10f2705127a52534867cee43368ed1b
Signed-off-by: Anton Shamin <anton.shamin@intel.com>
Signed-off-by: Serguei Katkov <serguei.i.katkov@intel.com>