ld: Update phase_enum/relro_enum and add seg_align_type

ld: Update phase_enum/relro_enum and add seg_align_type

Update GNU_RELRO date type so that they can also be used for text-only
LOAD segment.

	* ldexp.h (phase_enum): Rename exp_dataseg_none,
	exp_dataseg_align_seen, exp_dataseg_relro_seen,
	exp_dataseg_end_seen, exp_dataseg_relro_adjust,
	exp_dataseg_adjust and exp_dataseg_done to exp_seg_none,
	exp_seg_align_seen, exp_seg_relro_seen, exp_seg_end_seen,
	exp_seg_relro_adjust, exp_seg_adjust and exp_seg_done.
	(relro_enum): Rename exp_dataseg_relro_none,
	exp_dataseg_relro_start and exp_dataseg_relro_end to
	exp_seg_relro_none, exp_seg_relro_start and exp_seg_relro_end.
	(seg_align_type): New struct type.
	(ldexp_control): Use seg_align_type.
	* ldexp.c (fold_unary): Updated.
	(fold_binary): Likewise.
	* ldlang.c (strip_excluded_output_sections): Likewise.
	(lang_size_sections_1): Likewise.
	(lang_size_sections): Likewise.