Debugger: Track a counter when entering stepping.

This allows us to poll coreState and know if a new stepping needs to be
sent.  This is useful to allow e.g. regs to show changes per step.

Core/Core.cpp

@@ -54,6 +54,7 @@ static std::mutex m_hStepMutex;
 static std::condition_variable m_InactiveCond;
 static std::mutex m_hInactiveMutex;
 static bool singleStepPending = false;
+static int steppingCounter = 0;
 static std::set<Core_ShutdownFunc> shutdownFuncs;
 static bool windowHidden = false;
 static double lastActivity = 0.0;
@@ -334,10 +335,15 @@ void Core_EnableStepping(bool step) {
 		sleep_ms(1);
 		host->SetDebugMode(true);
 		Core_UpdateState(CORE_STEPPING);
+		steppingCounter++;
 	} else {
 		host->SetDebugMode(false);
 		coreState = CORE_RUNNING;
 		coreStatePending = false;
 		m_StepCond.notify_all();
 	}
 }
+
+int Core_GetSteppingCounter() {
+	return steppingCounter;
+}

Core/Core.h

@@ -31,12 +31,12 @@ void Core_ErrorPause();
 // For platforms that don't call Core_Run
 void Core_SetGraphicsContext(GraphicsContext *ctx);
 
-void Core_RunRenderThreadFrame();
-
 // called from gui
 void Core_EnableStepping(bool step);
 void Core_DoSingleStep();
 void Core_UpdateSingleStep();
+// Changes every time we enter stepping.
+int Core_GetSteppingCounter();
 
 typedef void (* Core_ShutdownFunc)();
 void Core_ListenShutdown(Core_ShutdownFunc func);