Update pc-relative support.

Update pc-relative support.

2019-06-28  Michael Meissner  <meissner@linux.ibm.com>

	* config/rs6000/predicates.md (pcrel_address):  Use
	SYMBOL_REF_LOCAL_P to determine if a label is local.
	(pcrel_external_address): New predicate.
	(non_prefixed_mem_operand): Delete, predicate not used.
	* config/rs6000/rs6000.h (SYMBOL_FLAG_PCREL_P): Delete, we now use
	SYMBOL_REF_LOCAL_P to determine if we can use pc-relative
	addressing.
	(SYMBOL_REF_PCREL_P): Likewise.

From-SVN: r272792