testsuite: aarch64: Add tests for vmlXl_high intrinsics

testsuite: aarch64: Add tests for vmlXl_high intrinsics

Add tests for vmlal_high_* and vmlsl_high_* Neon intrinsics. Since
these intrinsics are only supported for AArch64, these tests are
restricted to only run on AArch64 targets.

gcc/testsuite/ChangeLog:

2021-01-31  Jonathan Wright  <jonathan.wright@arm.com>

	* gcc.target/aarch64/advsimd-intrinsics/vmlXl_high.inc:
	New test template.
	* gcc.target/aarch64/advsimd-intrinsics/vmlXl_high_lane.inc:
	New test template.
	* gcc.target/aarch64/advsimd-intrinsics/vmlXl_high_laneq.inc:
	New test template.
	* gcc.target/aarch64/advsimd-intrinsics/vmlXl_high_n.inc:
	New test.
	* gcc.target/aarch64/advsimd-intrinsics/vmlal_high.c:
	New test.
	* gcc.target/aarch64/advsimd-intrinsics/vmlal_high_lane.c:
	New test.
	* gcc.target/aarch64/advsimd-intrinsics/vmlal_high_laneq.c:
	New test.
	* gcc.target/aarch64/advsimd-intrinsics/vmlal_high_n.c:
	New test.
	* gcc.target/aarch64/advsimd-intrinsics/vmlsl_high.c:
	New test.
	* gcc.target/aarch64/advsimd-intrinsics/vmlsl_high_lane.c:
	New test.
	* gcc.target/aarch64/advsimd-intrinsics/vmlsl_high_laneq.c:
	New test.
	* gcc.target/aarch64/advsimd-intrinsics/vmlsl_high_n.c:
	New test.