aarch64: Add support for preserve_none function attribute [PR target/118328]

aarch64: Add support for preserve_none function attribute [PR target/118328]

When applied to a function preserve_none changes the procedure call standard
such that all registers except stack pointer, frame register, and link register
are caller saved. Additionally, it changes the argument passing registers.

	PR target/118328

gcc/ChangeLog:

	* config/aarch64/aarch64.cc (handle_aarch64_vector_pcs_attribute):
	Add handling for ARM_PCS_PRESERVE_NONE.
	(aarch64_pcs_exclusions): New definition.
	(aarch64_gnu_attributes): Add entry for preserve_none and add
	aarch64_pcs_exclusions to aarch64_vector_pcs entry.
	(aarch64_preserve_none_abi): New function.
	(aarch64_fntype_abi): Add handling for preserve_none.
	(aarch64_reg_save_mode): Add handling for ARM_PCS_PRESERVE_NONE.
	(aarch64_hard_regno_call_part_clobbered): Add handling for
	ARM_PCS_PRESERVE_NONE.
	(num_pcs_arg_regs): New helper function.
	(get_pcs_arg_reg): New helper function.
	(aarch64_function_ok_for_sibcall): Add handling for ARM_PCS_PRESERVE_NONE.
	(aarch64_layout_arg): Add preserve_none argument lauout..
	(function_arg_preserve_none_regno_p): New helper function.
	(aarch64_function_arg): Update to handle preserve_none.
	(function_arg_preserve_none_regno_p): Update logic for preserve_none.
	(aarch64_expand_builtin_va_start): Add preserve_none layout.
	(aarch64_setup_incoming_varargs): Add preserve_none layout.
	(aarch64_is_variant_pcs): Update for case of ARM_PCS_PRESERVE_NONE.
	(aarch64_comp_type_attributes): Add preserve_none.
	* config/aarch64/aarch64.h (NUM_PRESERVE_NONE_ARG_REGS): New macro.
	(PRESERVE_NONE_REGISTERS): New macro.
	(enum arm_pcs): Add ARM_PCS_PRESERVE_NONE.
	* doc/extend.texi (preserve_none): Add docs for new attribute.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/preserve_none_1.c: New test.
	* gcc.target/aarch64/preserve_none_mingw_1.c: New test.
	* gcc.target/aarch64/preserve_none_2.c: New test.
	* gcc.target/aarch64/preserve_none_3.c: New test.
	* gcc.target/aarch64/preserve_none_4.c: New test.
	* gcc.target/aarch64/preserve_none_5.c: New test.
	* gcc.target/aarch64/preserve_none_6.c: New test.