Fifo: Make SyncGPUReason an enum class

Source/Core/VideoCommon/Fifo.h

@@ -20,15 +20,15 @@ void UpdateWantDeterminism(bool want);
 bool UseDeterministicGPUThread();
 
 // Used for diagnostics.
-enum SyncGPUReason
+enum class SyncGPUReason
 {
-  SYNC_GPU_OTHER,
-  SYNC_GPU_WRAPAROUND,
-  SYNC_GPU_EFB_POKE,
-  SYNC_GPU_PERFQUERY,
-  SYNC_GPU_BBOX,
-  SYNC_GPU_SWAP,
-  SYNC_GPU_AUX_SPACE,
+  Other,
+  Wraparound,
+  EFBPoke,
+  PerfQuery,
+  BBox,
+  Swap,
+  AuxSpace,
 };
 // In deterministic GPU thread mode this waits for the GPU to be done with pending work.
 void SyncGPU(SyncGPUReason reason, bool may_move_read_ptr = true);