[NDS32] Implment setmem pattern.
gcc/
* config/nds32/nds32-protos.h (nds32_expand_setmem): Declare.
* config/nds32/nds32-multiple.md (setmemsi): Define.
* config/nds32/nds32-memory-manipulation.c
(nds32_gen_dup_4_byte_to_word_value): New.
(emit_setmem_word_loop): New.
(emit_setmem_byte_loop): New.
(nds32_expand_setmem_loop): New.
(nds32_expand_setmem_loop_v3m): New.
(nds32_expand_setmem_unroll): New.
(nds32_expand_setmem): New.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@258239 138bc75d-0d04-0410-961f-82ee72b054a4