Qt: Fix race conditions initializing GDB stub

CHANGES

@@ -14,6 +14,7 @@ Other fixes:
  - GBA Cheats: Fix PARv3 Thumb hooks
  - mGUI: Fix crash if last loaded ROM directory disappears (fixes mgba.io/i/1466)
  - Libretro: Fix crash changing allowing opposing directions (hhromic)
+ - Qt: Fix race conditions initializing GDB stub
 Misc:
  - Qt: Make mute menu option also toggle fast-forward mute (fixes mgba.io/i/1424)
  - Qt: Show error message if file failed to load

src/platform/qt/CoreController.cpp

@@ -261,6 +261,7 @@ void CoreController::setDebugger(mDebugger* debugger) {
 	Interrupter interrupter(this);
 	if (debugger) {
 		mDebuggerAttach(debugger, m_threadContext.core);
+		mDebuggerEnter(debugger, DEBUGGER_ENTER_ATTACHED, 0);
 	} else {
 		m_threadContext.core->detachDebugger(m_threadContext.core);
 	}

src/platform/qt/DebuggerController.cpp

@@ -46,7 +46,6 @@ void DebuggerController::attach() {
 	if (m_gameController) {
 		attachInternal();
 		m_gameController->setDebugger(m_debugger);
-		mDebuggerEnter(m_debugger, DEBUGGER_ENTER_ATTACHED, 0);
 	} else {
 		m_autoattach = true;
 	}

src/platform/qt/GDBController.cpp

@@ -34,10 +34,10 @@ void GDBController::setBindAddress(uint32_t bindAddress) {
 }
 
 void GDBController::listen() {
-	if (!isAttached()) {
-		attach();
-	}
 	if (GDBStubListen(&m_gdbStub, m_port, &m_bindAddress)) {
+		if (!isAttached()) {
+			attach();
+		}
 		emit listening();
 	} else {
 		detach();