32-bit unwind data for ia64-hpux, from Steve Ellcey

32-bit unwind data for ia64-hpux, from Steve Ellcey
	* config/tc-ia64.c (special_section): Add SPECIAL_SECTION_INIT_ARRAY
	and SPECIAL_SECTION_FINI_ARRAY.
	(special_section_name): Add .init_array and .fini_array.
	(md_pseudo_table): Add init_array and fini_array.
	(md): Add pointer_size and pointer_size_shift fields.
	(setup_unwind_header): New static function.
	(output_unw_records): Modify to use setup_unwind_header.
	(generate_unwind_image, dot_endp): Modify to use md.pointer_size and
	md.pointer_size_shift.
	(md_begin): Initialize md.pointer_size and md.pointer_size_shift.