kernel/arm64: implement iframe stack and unwinding

Change-Id: I1587c1f57bd73777a188bb8f1bc58263de82fcb9
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5684
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>
Reviewed-by: David Karoly <karolyd577@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>

ARM64: Add initial kernel headers

Signed-off-by: Augustin Cavalier <waddlesplash@gmail.com>
aarch64 -> arm64 and coding style fixes by me.