Rename DR_ALIGNED_TO to DR_OFFSET_ALIGNMENT

Rename DR_ALIGNED_TO to DR_OFFSET_ALIGNMENT

This patch renames DR_ALIGNED_TO to DR_OFFSET_ALIGNMENT, to avoid
confusion with the upcoming DR_BASE_ALIGNMENT.  Nothing needed the
value as a tree, and the value is clipped to BIGGEST_ALIGNMENT
(maybe it should be MAX_OFILE_ALIGNMENT?) so we might as well use
an unsigned int instead.

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

gcc/
	* tree-data-ref.h (innermost_loop_behavior): Replace aligned_to
	with offset_alignment.
	(DR_ALIGNED_TO): Delete.
	(DR_OFFSET_ALIGNMENT): New macro.
	* tree-vectorizer.h (STMT_VINFO_DR_ALIGNED_TO): Delete.
	(STMT_VINFO_DR_OFFSET_ALIGNMENT): New macro.
	* tree-data-ref.c (dr_analyze_innermost): Update after above changes.
	(create_data_ref): Likewise.
	* tree-vect-data-refs.c (vect_compute_data_ref_alignment): Likewise.
	(vect_analyze_data_refs): Likewise.
	* tree-if-conv.c (if_convertible_loop_p_1): Use memset before
	creating dummy innermost behavior.

From-SVN: r249914