nir/i965/anv/radv/gallium: make shader info a pointer

When restoring something from shader cache we won't have and don't
want to create a nir_shader this change detaches the two.

There are other advantages such as being able to reuse the
shader info populated by GLSL IR.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/compiler/nir/nir_lower_clip.c

@@ -287,7 +287,7 @@ lower_clip_fs(nir_function_impl *impl, unsigned ucp_enables,
          discard->src[0] = nir_src_for_ssa(cond);
          nir_builder_instr_insert(&b, &discard->instr);
 
-         b.shader->info.fs.uses_discard = true;
+         b.shader->info->fs.uses_discard = true;
       }
    }
 }