[NDS32] Refine load_multiple and store_multiple.

[NDS32] Refine load_multiple and store_multiple.

gcc/
	* config/nds32/nds32-protos.h
	(nds32_expand_load_multiple): New arguments.
	(nds32_expand_store_multiple): Ditto.
	(nds32_valid_multiple_load_store): Rename ...
	(nds32_valid_multiple_load_store_p): ... to this.
	* config/nds32/nds32-memory-manipulation.c
	(nds32_expand_load_multiple): Refine implementation.
	(nds32_expand_store_multiple): Ditto.
	* config/nds32/nds32-multiple.md
	(load_multiple): Update nds32_expand_load_multiple interface.
	(store_multiple): Update nds32_expand_store_multiple interface.
	* config/nds32/nds32-predicates.c
	(nds32_valid_multiple_load_store): Rename ...
	(nds32_valid_multiple_load_store_p): ... to this and refine
	implementation.
	* config/nds32/predicates.md
	(nds32_load_multiple_and_update_address_operation): New predicate.
	(nds32_store_multiple_and_update_address_operation): New predicate.

Co-Authored-By: Chung-Ju Wu <jasonwucj@gmail.com>
Co-Authored-By: Monk Chiang <sh.chiang04@gmail.com>
From-SVN: r258234