2015-10-22  Richard Biener  <rguenther@suse.de>

	PR middle-end/68046
	PR middle-end/61893
	* optabs.c (emit_libcall_block_1): Allow a NULL_RTX equiv.
	(expand_binop): For -ftrapv optabs do not record an REG_EQUAL note.
	(expand_unop): Likewise.

	* gcc.dg/torture/ftrapv-2.c: New testcase.

From-SVN: r229170