S/390: Remove UNSPEC_LTREL_BASE

S/390: Remove UNSPEC_LTREL_BASE

It was needed only for g5/g6 machines, which are now gone.

gcc/ChangeLog:

2018-09-06  Ilya Leoshkevich  <iii@linux.ibm.com>

	* config/s390/s390.c (s390_decompose_constant_pool_ref):
	Remove UNSPEC_LTREL_BASE check.
	(annotate_constant_pool_refs): Likewise.
	(find_constant_pool_ref): Likewise.
	(find_ltrel_base): Removed.
	(replace_ltrel_base): Removed.
	(s390_mainpool_finish): Remove replace_ltrel_base call.
	(s390_chunkify_start): Remove pending LTREL_BASE logic.
	(s390_chunkify_finish): Remove replace_ltrel_base call.
	* config/s390/s390.md: Remove UNSPEC_LTREL_BASE.

From-SVN: r264141