st/nir: run st_nir_opts after 64bit ops lowering

CID: 1444309
Fixes: 9ab1b1d022 "st/nir: Move 64-bit lowering later"
Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/mesa/state_tracker/st_glsl_to_nir.cpp

@@ -436,7 +436,7 @@ st_glsl_to_nir(struct st_context *st, struct gl_program *prog,
          lowered_64bit_ops |= progress;
       } while (progress);
 
-      if (progress)
+      if (lowered_64bit_ops)
          st_nir_opts(nir, is_scalar);
    }