PR middle-end/88968
	* gimplify.c (gimplify_omp_atomic): Handle bitfield atomics with
	non-integral DECL_BIT_FIELD_REPRESENTATIVEs.

	* c-omp.c (c_finish_omp_atomic): For bitfield atomics, update type
	variable after using BIT_FIELD_REF.

	* c-c++-common/gomp/atomic-23.c: New test.

From-SVN: r268165