RISC-V: Add test for vec_duplicate + vdiv.vv combine case 0 with GR2VR cost 0, 2...

RISC-V: Add test for vec_duplicate + vdiv.vv combine case 0 with GR2VR cost 0, 2 and 15

Add asm dump check test for vec_duplicate + vdiv.vv combine to vdiv.vx,
with the GR2VR cost is 0, 2 and 15.

The below test suites are passed for this patch.
* The rv64gcv fully regression test.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/vx_vf/vx-1-i16.c: Add asm check
	for vdiv.vx combine.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx-1-i32.c: Ditto.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx-1-i64.c: Ditto.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx-1-i8.c: Ditto.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx-2-i16.c: Ditto.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx-2-i32.c: Ditto.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx-2-i64.c: Ditto.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx-2-i8.c: Ditto.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx-3-i16.c: Ditto.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx-3-i32.c: Ditto.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx-3-i64.c: Ditto.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx-3-i8.c: Ditto.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx_binary_data.h: Add test
	data for vdiv run test.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx_vdiv-run-1-i16.c: New test.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx_vdiv-run-1-i32.c: New test.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx_vdiv-run-1-i64.c: New test.
	* gcc.target/riscv/rvv/autovec/vx_vf/vx_vdiv-run-1-i8.c: New test.

Signed-off-by: Pan Li <pan2.li@intel.com>