* Remove m_current_choice, it's not correct to rely on thread name entry. In extreme corner cases a newly thread can be created, old destroyed with the same entry name. (reoccuring LV2 SPU/PPU ID)
* Remove m_no_thread_selected, can be easily replaced with std::weak_ptr expired() function and is more accurate this way.
* In HandleBreakpointRequest: only remove breakpoint on valid PPU thread and not any thread! also fix potential nullptr deref if thread has recently been destroyed.
Fixes a corner case viewing unaligned memory at the end of spu memory.
Also unaligned view isn't suitable for the debugger, for these purposes the memory viewer should be used instead.
Remove "atomic operator" classes
Remove test, test_and_set, test_and_reset, test_and_complement global functions
Simplify atomic_t<> with constexpr if, remove some garbage
Redesign bs_t<> to use class, mark its methods constexpr
Implement atomic_bs_t<> for optimizations
Remove unused __bitwise_ops concept (should be in other header anyway)
Bitsets can now be tested via safe bool conversion
