[23/46] Make LOOP_VINFO_MAY_MISALIGN_STMTS use stmt_vec_info

[23/46] Make LOOP_VINFO_MAY_MISALIGN_STMTS use stmt_vec_info

This patch changes LOOP_VINFO_MAY_MISALIGN_STMTS from an
auto_vec<gimple *> to an auto_vec<stmt_vec_info>.

2018-07-31  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-vectorizer.h (_loop_vec_info::may_misalign_stmts): Change
	from an auto_vec<gimple *> to an auto_vec<stmt_vec_info>.
	* tree-vect-data-refs.c (vect_enhance_data_refs_alignment): Update
	accordingly.
	* tree-vect-loop-manip.c (vect_create_cond_for_align_checks): Likewise.

From-SVN: r263138