re PR middle-end/87574 (ICE in add_data_member_location_attribute at gcc/gcc/dwarf2out.c:19226 since r264943)

	PR middle-end/87574
	* cgraphunit.c (cgraph_node::expand_thunk): Force DECL_IGNORED_P on
	the thunk when expanding to GIMPLE.

From-SVN: r265028