[NDS32] Rewrite infrastructure for intrinsic.

[NDS32] Rewrite infrastructure for intrinsic.

gcc/
	* config/nds32/nds32-intrinsic.c
	(nds32_expand_builtin_null_ftype_reg): Delete.
	(nds32_expand_builtin_reg_ftype_imm): Ditto.
	(nds32_expand_builtin_null_ftype_reg_imm): Ditto.
	(nds32_read_argument): New.
	(nds32_legitimize_target): Ditto.
	(nds32_legitimize_argument): Ditto.
	(nds32_check_constant_argument): Ditto.
	(nds32_expand_unop_builtin): Ditto.
	(nds32_expand_unopimm_builtin): Ditto.
	(nds32_expand_binop_builtin): Ditto.
	(nds32_builtin_decl_impl): Ditto.
	(builtin_description): Ditto.
	(nds32_expand_builtin_impl): Rewrite with new infrastructure.
	(nds32_init_builtins_impl): Ditto.
	* config/nds32/nds32.c (TARGET_BUILTIN_DECL): Define.
	(nds32_builtin_decl): New.
	* config/nds32/nds32.h (nds32_builtins): Add NDS32_BUILTIN_COUNT.
	* config/nds32/nds32-protos.h (nds32_builtin_decl_impl): Declare.

Co-Authored-By: Chung-Ju Wu <jasonwucj@gmail.com>
Co-Authored-By: Kito Cheng <kito.cheng@gmail.com>
From-SVN: r258211