Adds suppport for INTEL_fragment_shader_ordering. We achieve
the fragment ordering by using the same instruction as for
beginInvocationInterlockARB() which is by issuing a memory
fence via sendc.
Signed-off-by: Kevin Rogovin <kevin.rogovin@intel.com>
Reviewed-by: Plamena Manolova <plamena.manolova@intel.com>