re PR rtl-optimization/33822 (-g -O -mstrict-align causes an ICE in set_variable_part,)

re PR rtl-optimization/33822 (-g -O -mstrict-align causes an ICE in set_variable_part,)

	PR rtl-optimization/33822
	* rtl.h (REG_OFFSET): Fix comment.
	* var-tracking.c (INT_MEM_OFFSET): New macro.
	(var_mem_set): Use it.
	(var_mem_delete_and_set): Likewise.
	(var_mem_delete): Likewise.
	(vt_get_decl_and_offset): Likewise.
	(offset_valid_for_tracked_p): New predicate.
	(count_uses): Do not track locations with invalid offsets.
	(add_uses): Likewise.
	(add_stores): Likewise.

From-SVN: r129972