[ARM/AArch64][testsuite] Add vsubhn, vraddhn and vrsubhn tests. Split vaddhn.c into vXXXhn.inc and vaddhn.c to share code with other new tests.

2015-01-26  Christophe Lyon  <christophe.lyon@linaro.org>

	* gcc.target/aarch64/advsimd-intrinsics/vXXXhn.inc: New file.
	* gcc.target/aarch64/advsimd-intrinsics/vraddhn.c: New file.
	* gcc.target/aarch64/advsimd-intrinsics/vrsubhn.c: New file.
	* gcc.target/aarch64/advsimd-intrinsics/vsubhn.c: New file.
	* gcc.target/aarch64/advsimd-intrinsics/vaddhn.c: Use code from
	vXXXhn.inc.

From-SVN: r220117