Make dr_analyze_innermost operate on innermost_loop_behavior

Make dr_analyze_innermost operate on innermost_loop_behavior

This means that callers to dr_analyze_innermost don't need a full
data_reference and don't need to fill in any fields beforehand.

2017-07-03  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* tree-data-ref.h (dr_analyze_innermost): Replace the dr argument
	with a "innermost_loop_behavior *" and refeence tree.
	* tree-data-ref.c (dr_analyze_innermost): Likewise.
	(create_data_ref): Update call accordingly.
	* tree-predcom.c (find_looparound_phi): Likewise.

From-SVN: r249913