gcc/cp/ChangeLog:

	PR c++/70347
	* typeck.c (process_init_constructor_union): If the initializer
	is empty, use the union's NSDMI if it has one.

gcc/testsuite/ChangeLog:

	PR c++/70347
	* g++.dg/cpp1y/nsdmi-union1.C: New test.

From-SVN: r234443