re PR tree-optimization/17591 (Ada bootstrap SEGV in stage2 on osint.adb, no SEGV...

re PR tree-optimization/17591 (Ada bootstrap SEGV in stage2 on osint.adb, no SEGV when -fno-ivopts)

	PR bootstrap/17591
	* tree-ssa-loop-im.c (for_each_index): Call callback for component_refs
	with varying offset.
	* tree-ssa-loop-ivopts.c (abnormal_ssa_name_p): New function.
	(idx_contains_abnormal_ssa_name_p): Scan step and lower bound for
	ARRAY_REFS.
	(expr_invariant_in_loop_p): New function.
	(idx_find_step): Handle step and lower bound for ARRAY_REFs.  Handle
	component_ref_field_offset for COMPONENT_REFs.  Do not allow
	ALIGN_INDIRECT_REFs and MISALIGNED_INDIRECT_REFs.
	(add_address_candidates): Do not handle ALIGN_INDIRECT_REFs and
	MISALIGNED_INDIRECT_REFs.
	(idx_remove_ssa_names): Handle step and lower bound for ARRAY_REFs.
	(rewrite_address_base): Do not handle ALIGN_INDIRECT_REFs and
	MISALIGNED_INDIRECT_REFs.

From-SVN: r88123