Core::SetState: Avoid Global System Accessor

Source/Core/Core/Core.cpp

@@ -354,9 +354,9 @@ static void CPUSetInitialExecutionState(bool force_paused = false)
 {
   // The CPU starts in stepping state, and will wait until a new state is set before executing.
   // SetState must be called on the host thread, so we defer it for later.
-  QueueHostJob([force_paused](Core::System&) {
+  QueueHostJob([force_paused](Core::System& system) {
     bool paused = SConfig::GetInstance().bBootToPause || force_paused;
-    SetState(paused ? State::Paused : State::Running);
+    SetState(system, paused ? State::Paused : State::Running);
     Host_UpdateDisasmDialog();
     Host_UpdateMainFrame();
     Host_Message(HostMessageID::WMUserCreate);
@@ -700,13 +700,12 @@ static void EmuThread(Core::System& system, std::unique_ptr<BootParameters> boot
 
 // Set or get the running state
 
-void SetState(State state, bool report_state_change)
+void SetState(Core::System& system, State state, bool report_state_change)
 {
   // State cannot be controlled until the CPU Thread is operational
   if (!IsRunningAndStarted())
     return;
 
-  auto& system = Core::System::GetInstance();
   switch (state)
   {
   case State::Paused:
@@ -1061,12 +1060,12 @@ void DoFrameStep(Core::System& system)
     // if already paused, frame advance for 1 frame
     s_stop_frame_step = false;
     s_frame_step = true;
-    SetState(State::Running, false);
+    SetState(system, State::Running, false);
   }
   else if (!s_frame_step)
   {
     // if not paused yet, pause immediately instead
-    SetState(State::Paused);
+    SetState(system, State::Paused);
   }
 }