PR27884, skip_attr_bytes: Assertion (data) <= (end) failed

	PR 27884
	* dwarf.c (get_type_abbrev_from_form): Replace cu_offset_return
	param with map_return, and return map for DW_FORM_ref_addr.
	(get_type_signedness): Adjust calls to get_type_abbrev_from_form.
	Pass returned cu map start and end to recursive call.
	(read_and_display_attr_value): Similarly.