[AArch64][10/14] Implement target pragmas

[AArch64][10/14] Implement target pragmas

	* config.gcc (aarch64*-*-*): Specify c_target_objs and cxx_target_objs.
	* config/aarch64/aarch64.h (REGISTER_TARGET_PRAGMAS): Define.
	(TARGET_CPU_CPP_BUILTINS): Redefine to call aarch64_cpu_cpp_builtins.
	* config/aarch64/aarch64.c (aarch64_override_options_internal): Remove
	static keyword.
	(aarch64_reset_previous_fndecl): New function.
	(aarch64_handle_attr_isa_flags): Handle "+nothing" in the beginning of
	the string.
	* config/aarch64/aarch64-c.c: New file.
	* config/aarch64/arm_acle.h: Add pragma +crc+nofp at the top.
	Push and pop options at beginning and end.  Remove ifdef
	__ARM_FEATURE_CRC32.
	* config/aarch64/arm_neon.h: Remove #ifdef check on __ARM_NEON.
	Add pragma +nothing+simd and +nothing+crypto where appropriate.
	* config/aarch64/t-aarch64 (aarch64-c.o): New rule.
	* config/aarch64/aarch64-protos.h (aarch64_cpu_cpp_builtins):
	Define prototype.
	(aarch64_register_pragmas): Likewise.
	(aarch64_reset_previous_fndecl): Likewise.
	(aarch64_process_target_attr): Likewise.
	(aarch64_override_options_internal): Likewise.

	* gcc.target/aarch64/arm_neon-nosimd-error.c: Delete.

From-SVN: r226563