JIT optimizations and refactoring (#675)

* CPU/Recompiler: Use rel32 call where possible for no-args

* JitCodeBuffer: Support using preallocated buffer

* CPU/Recompiler/AArch64: Use bl instead of blr for short branches

* CPU/CodeCache: Allocate recompiler buffer in program space

This means we don't need 64-bit moves for every call out of the
recompiler.

* GTE: Don't store as u16 and load as u32

* CPU/Recompiler: Add methods to emit global load/stores

* GTE: Convert class to namespace

* CPU/Recompiler: Call GTE functions directly

* Settings: Turn into a global variable

* GPU: Replace local pointers with global

* InterruptController: Turn into a global pointer

* System: Replace local pointers with global

* Timers: Turn into a global instance

* DMA: Turn into a global instance

* SPU: Turn into a global instance

* CDROM: Turn into a global instance

* MDEC: Turn into a global instance

* Pad: Turn into a global instance

* SIO: Turn into a global instance

* CDROM: Move audio FIFO to the heap

* CPU/Recompiler: Drop ASMFunctions

No longer needed since we have code in the same 4GB window.

* CPUCodeCache: Turn class into namespace

* Bus: Local pointer -> global pointers

* CPU: Turn class into namespace

* Bus: Turn into namespace

* GTE: Store registers in CPU state struct

Allows relative addressing on ARM.

* CPU/Recompiler: Align code storage to page size

* CPU/Recompiler: Fix relative branches on A64

* HostInterface: Local references to global

* System: Turn into a namespace, move events out

* Add guard pages

* Android: Fix build

src/core/timing_event.h

@@ -6,29 +6,24 @@
 
 #include "types.h"
 
-class System;
-class TimingEvent;
+class StateWrapper;
 
 // Event callback type. Second parameter is the number of cycles the event was executed "late".
 using TimingEventCallback = std::function<void(TickCount ticks, TickCount ticks_late)>;
 
 class TimingEvent
 {
-  friend System;
-
 public:
-  TimingEvent(System* system, std::string name, TickCount period, TickCount interval, TimingEventCallback callback);
+  TimingEvent(std::string name, TickCount period, TickCount interval, TimingEventCallback callback);
   ~TimingEvent();
 
-  System* GetSystem() const { return m_system; }
   const std::string& GetName() const { return m_name; }
   bool IsActive() const { return m_active; }
 
   // Returns the number of ticks between each event.
-  TickCount GetPeriod() const { return m_period; }
-  TickCount GetInterval() const { return m_interval; }
-
-  TickCount GetDowncount() const { return m_downcount; }
+  ALWAYS_INLINE TickCount GetPeriod() const { return m_period; }
+  ALWAYS_INLINE TickCount GetInterval() const { return m_interval; }
+  ALWAYS_INLINE TickCount GetDowncount() const { return m_downcount; }
 
   // Includes pending time.
   TickCount GetTicksSinceLastExecution() const;
@@ -61,14 +56,35 @@ public:
   void SetInterval(TickCount interval) { m_interval = interval; }
   void SetPeriod(TickCount period) { m_period = period; }
 
-private:
   TickCount m_downcount;
   TickCount m_time_since_last_run;
   TickCount m_period;
   TickCount m_interval;
 
   TimingEventCallback m_callback;
-  System* m_system;
   std::string m_name;
   bool m_active;
 };
+
+namespace TimingEvents {
+
+u32 GetGlobalTickCounter();
+
+void Initialize();
+void Reset();
+void Shutdown();
+
+/// Creates a new event.
+std::unique_ptr<TimingEvent> CreateTimingEvent(std::string name, TickCount period, TickCount interval,
+                                               TimingEventCallback callback, bool activate);
+
+/// Serialization.
+bool DoState(StateWrapper& sw, u32 global_tick_counter);
+
+void RunEvents();
+
+void UpdateCPUDowncount();
+
+
+
+} // namespace TimingEventManager