intel/compiler: invalidate all metadata in brw_nir_lower_intersection_shader

New "if" blocks were inserted.

Fixes: 303378e1dd ("intel/rt: Add lowering for combined intersection/any-hit shaders")
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jason Ekstrand <jason.ekstrand@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15924>

src/intel/compiler/brw_nir_lower_intersection_shader.c

@@ -246,6 +246,7 @@ brw_nir_lower_intersection_shader(nir_shader *intersection,
          }
       }
    }
+   nir_metadata_preserve(impl, nir_metadata_none);
 
    /* We did some inlining; have to re-index SSA defs */
    nir_index_ssa_defs(impl);