Fix PR c++/42217

gcc/cp/ChangeLog
	PR c++/42217
	* class.c (remove_zero_width_bit_fields): The width of the bit field is
	in DECL_SIZE, not in DECL_INITIAL.

gcc/testsuite/ChangeLog
	PR c++/42217
	* g++.dg/other/bitfield4.C: New test.

From-SVN: r154938