WASAPI: Fix a deadlock in loopback mode when stopping the device.

This happens when stopping the device while nothing is being played and
is due to how WASAPI does not signal an event in loopback mode when
nothing is being played.

miniaudio.h

@@ -8528,6 +8528,22 @@ ma_result ma_device_reroute__wasapi(ma_device* pDevice, ma_device_type deviceTyp
 }
 
 
+ma_result ma_device_stop__wasapi(ma_device* pDevice)
+{
+    ma_assert(pDevice != NULL);
+
+    /*
+    We need to explicitly signal the capture event in loopback mode to ensure we return from WaitForSingleObject() when nothing is being played. When nothing
+    is being played, the event is never signalled internally by WASAPI which means we will deadlock when stopping the device.
+    */
+    if (pDevice->type == ma_device_type_loopback) {
+        SetEvent((HANDLE)pDevice->wasapi.hEventCapture);
+    }
+
+    return MA_SUCCESS;
+}
+
+
 ma_result ma_device_main_loop__wasapi(ma_device* pDevice)
 {
     ma_result result;
@@ -9093,8 +9109,8 @@ ma_result ma_context_init__wasapi(const ma_context_config* pConfig, ma_context*
     pContext->onGetDeviceInfo  = ma_context_get_device_info__wasapi;
     pContext->onDeviceInit     = ma_device_init__wasapi;
     pContext->onDeviceUninit   = ma_device_uninit__wasapi;
-    pContext->onDeviceStart    = NULL; /* Not used. Started in onDeviceMainLoop. */
-    pContext->onDeviceStop     = NULL; /* Not used. Stopped in onDeviceMainLoop. */
+    pContext->onDeviceStart    = NULL;                      /* Not used. Started in onDeviceMainLoop. */
+    pContext->onDeviceStop     = ma_device_stop__wasapi;    /* Required to ensure the capture event is signalled when stopping a loopback device while nothing is playing. */
     pContext->onDeviceMainLoop = ma_device_main_loop__wasapi;
 
     return result;
@@ -25740,14 +25756,14 @@ ma_result ma_device_stop(ma_device* pDevice)
 
         /* There's no need to wake up the thread like we do when starting. */
 
+        if (pDevice->pContext->onDeviceStop) {
+            result = pDevice->pContext->onDeviceStop(pDevice);
+        } else {
+            result = MA_SUCCESS;
+        }
+
         /* Asynchronous backends need to be handled differently. */
         if (ma_context_is_backend_asynchronous(pDevice->pContext)) {
-            if (pDevice->pContext->onDeviceStop) {
-                result = pDevice->pContext->onDeviceStop(pDevice);
-            } else {
-                result = MA_SUCCESS;
-            }
-
             ma_device__set_state(pDevice, MA_STATE_STOPPED);
         } else {
             /* Synchronous backends. */