intel/nir: Lowering image loads and stores trashes all metadata

intel/nir: Lowering image loads and stores trashes all metadata

This fixes the GL_ARB_fragment_shader_interlock piglit test on gen8
platforms where the lack of metadata dirtying was causing another pass
to accidentally delete a much needed loop.

https://bugs.freedesktop.org/show_bug.cgi?id=107745
Fixes: 37f7983bcca1 "intel/compiler: Do image load/store lowering..."
Jason Ekstrand <jason@jlekstrand.net> writes:
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>