st/mesa: silenced unhanded enum warning in st_glsl_to_tgsi.cpp

Add ir_intrinsic_begin_fragment_shader_ordering switch case to
silence warning

Reviewed-by: Mathias Fröhlich <Mathias.Froehlich@web.de>

src/mesa/state_tracker/st_glsl_to_tgsi.cpp

@@ -4068,6 +4068,7 @@ glsl_to_tgsi_visitor::visit(ir_call *ir)
    case ir_intrinsic_generic_atomic_comp_swap:
    case ir_intrinsic_begin_invocation_interlock:
    case ir_intrinsic_end_invocation_interlock:
+   case ir_intrinsic_begin_fragment_shader_ordering:
       unreachable("Invalid intrinsic");
    }
 }