* class.c (build_base_field_1): Split out from...
	(build_base_field): ...here.  In C++17 mode, build a field for
	empty bases.
	* decl.c (xref_basetypes): In C++17 aggregates can have bases.
	(next_initializable_field): Allow base fields in C++17.
	* typeck2.c (process_init_constructor_record): Likewise.

From-SVN: r241187