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/cdrom.h

@@ -12,20 +12,16 @@
 #include <vector>
 
 class StateWrapper;
-
-class System;
 class TimingEvent;
-class DMA;
-class InterruptController;
-class SPU;
 
-class CDROM
+class CDROM final
 {
 public:
   CDROM();
   ~CDROM();
 
-  void Initialize(System* system, DMA* dma, InterruptController* interrupt_controller, SPU* spu);
+  void Initialize();
+  void Shutdown();
   void Reset();
   bool DoState(StateWrapper& sw);
 
@@ -276,10 +272,6 @@ private:
   template<bool STEREO, bool SAMPLE_RATE>
   void ResampleXAADPCM(const s16* frames_in, u32 num_frames_in);
 
-  System* m_system = nullptr;
-  DMA* m_dma = nullptr;
-  InterruptController* m_interrupt_controller = nullptr;
-  SPU* m_spu = nullptr;
   std::unique_ptr<TimingEvent> m_command_event;
   std::unique_ptr<TimingEvent> m_drive_event;
 
@@ -347,5 +339,7 @@ private:
   CDROMAsyncReader m_reader;
 
   // two 16-bit samples packed in 32-bits
-  InlineFIFOQueue<u32, AUDIO_FIFO_SIZE> m_audio_fifo;
+  HeapFIFOQueue<u32, AUDIO_FIFO_SIZE> m_audio_fifo;
 };
+
+extern CDROM g_cdrom;