aarch64: add vector sin, cos, log and pow abi symbols

aarch64: add vector sin, cos, log and pow abi symbols

Add simple assembly implementations that fall back to scalar code,
similar to the vector exp code.

2019-07-15  Szabolcs Nagy  <szabolcs.nagy@arm.com>

	* sysdeps/aarch64/fpu/Makefile: Add functions.
	* sysdeps/aarch64/fpu/Versions: Add symbols.
	* sysdeps/aarch64/fpu/libmvec_double_vlen2_cos.S: New file.
	* sysdeps/aarch64/fpu/libmvec_double_vlen2_log.S: New file.
	* sysdeps/aarch64/fpu/libmvec_double_vlen2_pow.S: New file.
	* sysdeps/aarch64/fpu/libmvec_double_vlen2_sin.S: New file.
	* sysdeps/aarch64/fpu/libmvec_float_vlen4_cosf.S: New file.
	* sysdeps/aarch64/fpu/libmvec_float_vlen4_logf.S: New file.
	* sysdeps/aarch64/fpu/libmvec_float_vlen4_powf.S: New file.
	* sysdeps/aarch64/fpu/libmvec_float_vlen4_sinf.S: New file.
	* sysdeps/aarch64/fpu/test-double-vlen2-wrappers.c: Add wrappers.
	* sysdeps/aarch64/fpu/test-float-vlen4-wrappers.c: Add wrappers.
	* sysdeps/aarch64/libm-test-ulps: Update.
	* sysdeps/unix/sysv/linux/aarch64/libmvec.abilist: Update.