GAS: Allow AArch64 pseudo-ops to accept the command line separator character.

	PR 29519
	* config/tc-aarch64.c (s_unreq): Use find_end_of_line().
	(s_aarch64_cpu): Likewise.
	(s_aarch64_arch): Likewise.
	(s_aarch64_arch_extension): Likewise.
	* testsuite/gas/aarch64/pr29519.d: New test driver file.
	* testsuite/gas/aarch64/pr29519.s: New test source file.