AArch64: Add test for -mcpu=native

AArch64: Add test for -mcpu=native

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/cpunative/aarch64-cpunative.exp: New file.
	* gcc.target/aarch64/cpunative/info_0: New test.
	* gcc.target/aarch64/cpunative/info_1: New test.
	* gcc.target/aarch64/cpunative/info_10: New test.
	* gcc.target/aarch64/cpunative/info_11: New test.
	* gcc.target/aarch64/cpunative/info_12: New test.
	* gcc.target/aarch64/cpunative/info_13: New test.
	* gcc.target/aarch64/cpunative/info_14: New test.
	* gcc.target/aarch64/cpunative/info_15: New test.
	* gcc.target/aarch64/cpunative/info_2: New test.
	* gcc.target/aarch64/cpunative/info_3: New test.
	* gcc.target/aarch64/cpunative/info_4: New test.
	* gcc.target/aarch64/cpunative/info_5: New test.
	* gcc.target/aarch64/cpunative/info_6: New test.
	* gcc.target/aarch64/cpunative/info_7: New test.
	* gcc.target/aarch64/cpunative/info_8: New test.
	* gcc.target/aarch64/cpunative/info_9: New test.
	* gcc.target/aarch64/cpunative/native_cpu_0.c: New test.
	* gcc.target/aarch64/cpunative/native_cpu_1.c: New test.
	* gcc.target/aarch64/cpunative/native_cpu_10.c: New test.
	* gcc.target/aarch64/cpunative/native_cpu_13.c: New test.
	* gcc.target/aarch64/cpunative/native_cpu_14.c: New test.
	* gcc.target/aarch64/cpunative/native_cpu_2.c: New test.
	* gcc.target/aarch64/cpunative/native_cpu_3.c: New test.
	* gcc.target/aarch64/cpunative/native_cpu_4.c: New test.
	* gcc.target/aarch64/cpunative/native_cpu_5.c: New test.
	* gcc.target/aarch64/cpunative/native_cpu_6.c: New test.
	* gcc.target/aarch64/cpunative/native_cpu_7.c: New test.
	* gcc.target/aarch64/cpunative/native_cpu_8.c: New test.

(cherry picked from commit 8bc83ee378e1cac65d75752b5137ec35d9e1aca1)