Hi all,

this patch splits and restructures the aarch64 bti pass code in order
to have it usable by the arm backend as well.  These changes have no
functional impact.

The original patch was approved here:
<https://gcc.gnu.org/pipermail/gcc-patches/2022-May/594172.html>.

After that Richard E. noted that was better to move the new pass
definition for arm in the following patch and so I did.

Best Regards

  Andrea

gcc/Changelog

	* config.gcc (aarch64*-*-*): Rename 'aarch64-bti-insert.o' into
	'aarch-bti-insert.o'.
	* config/aarch64/aarch64-protos.h: Remove 'aarch64_bti_enabled'
	proto.
	* config/aarch64/aarch64.cc (aarch_bti_enabled): Rename.
	(aarch_bti_j_insn_p, aarch_pac_insn_p): New functions.
	(aarch64_output_mi_thunk)
	(aarch64_print_patchable_function_entry)
	(aarch64_file_end_indicate_exec_stack): Update renamed function
	calls to renamed functions.
	* config/aarch64/t-aarch64 (aarch-bti-insert.o): Update target.
	* config/arm/aarch-bti-insert.cc: New file including and
	generalizing code from aarch64-bti-insert.cc.
	* config/arm/aarch-common-protos.h: Update.