gcc/

gcc/
	* defaults.h (HAVE_mem_thread_fence, gen_mem_thread_fence)
	(HAVE_memory_barrier, gen_memory_barrier, HAVE_mem_signal_fence)
	(gen_mem_signal_fence): Delete.
	* target-insns.def (mem_signal_fence, mem_thread_fence)
	(memory_barrier): New targetm instruction patterns.
	* optabs.c (expand_mem_thread_fence): Use them instead of HAVE_*/gen_*
	interface.
	(expand_mem_signal_fence): Likewise.

From-SVN: r225209