i965/fs: Handle MRF destinations in lower_integer_multiplication().
The lowered code reads from the destination, which isn't possible from message registers. Fixes the following dEQP tests on SNB: dEQP-GLES3.functional.shaders.precision.int.highp_mul_fragment dEQP-GLES3.functional.shaders.precision.int.mediump_mul_fragment dEQP-GLES3.functional.shaders.precision.int.lowp_mul_fragment Cc: "10.6 11.0" <mesa-stable@lists.freedesktop.org> Tested-by:Mark Janes <mark.a.janes@intel.com> Reviewed-by:
Kenneth Graunke <kenneth@whitecape.org> Reviewed-by:
Jason Ekstrand <jason.ekstrand@intel.com> (cherry picked from commit 9390cb84)