[NDS32] Add intrinsic functions for particular instructions.

[NDS32] Add intrinsic functions for particular instructions.

gcc/
	* config/nds32/constants.md (unspec_element, unspec_volatile_element):
	Add enum values for particular instructions.
	* config/nds32/nds32-intrinsic.c: Implementation of expanding
	particular intrinsic functions.
	* config/nds32/nds32-intrinsic.md: Likewise.
	* config/nds32/nds32_intrinsic.h: Likewise.
	* config/nds32/nds32.h (nds32_builtins): Likewise.
	* config/nds32/nds32.md (type): Add pbsad and pbsada.
	(btst, ave): New patterns for particular instructions.

From-SVN: r259208