LoongArch: Add standard patterns uabd and sabd

gcc/ChangeLog:

	* config/loongarch/lasx.md (lasx_xvabsd_s_<lasxfmt>): Remove.
	(<su>abd<mode>3): New insn pattern.
	(lasx_xvabsd_u_<lasxfmt_u>): Remove.
	* config/loongarch/loongarch-builtins.cc (CODE_FOR_lsx_vabsd_b):
	Rename.
	(CODE_FOR_lsx_vabsd_h): Ditto.
	(CODE_FOR_lsx_vabsd_w): Ditto.
	(CODE_FOR_lsx_vabsd_d): Ditto.
	(CODE_FOR_lsx_vabsd_bu): Ditto.
	(CODE_FOR_lsx_vabsd_hu): Ditto.
	(CODE_FOR_lsx_vabsd_wu): Ditto.
	(CODE_FOR_lsx_vabsd_du): Ditto.
	(CODE_FOR_lasx_xvabsd_b): Ditto.
	(CODE_FOR_lasx_xvabsd_h): Ditto.
	(CODE_FOR_lasx_xvabsd_w): Ditto.
	(CODE_FOR_lasx_xvabsd_d): Ditto.
	(CODE_FOR_lasx_xvabsd_bu): Ditto.
	(CODE_FOR_lasx_xvabsd_hu): Ditto.
	(CODE_FOR_lasx_xvabsd_wu): Ditto.
	(CODE_FOR_lasx_xvabsd_du): Ditto.
	* config/loongarch/loongarch.md (u): Add smax/umax.
	* config/loongarch/lsx.md (SU_MAX): New iterator.
	(su_min): New attr.
	(lsx_vabsd_s_<lsxfmt>): Remove.
	(<su>abd<mode>3): New insn pattern.
	(lsx_vabsd_u_<lsxfmt_u>): Remove.

gcc/testsuite/ChangeLog:

	* gcc.target/loongarch/abd-lasx.c: New test.
	* gcc.target/loongarch/abd-lsx.c: New test.