Investigate changes to UnfairSemaphore spinning on ARM64 and tune as necessary

[kouvel]

Fix and enable CLRLifoSemaphore's new spinning scheme on ARM64 and retune as necessary such that one scheme works on all processors.

PR that added the new spinning scheme and disabled it on ARM64: dotnet/coreclr#13921

[kouvel]

Not likely to happen, access to this hardware is rather limited and this is no reason to believe there is something to fix