Audit arm exclusive monitor use for cache line sharing

DR is using exclusive monitors (load-exclusive + store-exclusive pairs) to implement atomic operations for AArch32 and AArch64. However, the Exclusives Reservation Granule is typically a cache line, and within this size two monitors cannot be distinguished. It seems quite possible that two global locks are declared next to each other and on the same line. This issue covers looking for such problems and using alignment declarations or other remedies.