make side_effects a vec<rtx>

gcc/ChangeLog:

2016-07-06  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>

	* var-tracking.c (struct adjust_mem_data): Make side_effects a vector.
	(adjust_mems): Adjust.
	(adjust_insn): Likewise.
	(prepare_call_arguments): Likewise.

From-SVN: r238066