Services/GSP: Mark the thread ids as unused when a GSP session is destroyed.

This fixes the games that call RegisterInterruptRelayQueue and UnregisterInterruptRelayQueue frequently.

src/core/hle/service/gsp/gsp_gpu.cpp

@@ -362,12 +362,9 @@ void GSP_GPU::UnregisterInterruptRelayQueue(Kernel::HLERequestContext& ctx) {
     IPC::RequestParser rp(ctx, 0x14, 0, 0);
 
     SessionData* session_data = GetSessionData(ctx.Session());
-    session_data->thread_id = 0;
     session_data->interrupt_event = nullptr;
     session_data->registered = false;
 
-    // TODO(Subv): Reset next_thread_id so that it doesn't go past the maximum of 4.
-
     IPC::RequestBuilder rb = rp.MakeBuilder(1, 0);
     rb.Push(RESULT_SUCCESS);
 
@@ -768,5 +765,10 @@ SessionData::SessionData() {
     used_thread_ids[thread_id] = true;
 }
 
+SessionData::~SessionData() {
+    // Free the thread id slot so that other sessions can use it.
+    used_thread_ids[thread_id] = false;
+}
+
 } // namespace GSP
 } // namespace Service

src/core/hle/service/gsp/gsp_gpu.h

@@ -181,6 +181,7 @@ static_assert(sizeof(CommandBuffer) == 0x200, "CommandBuffer struct has incorrec
 
 struct SessionData : public Kernel::SessionRequestHandler::SessionDataBase {
     SessionData();
+    ~SessionData();
 
     /// Event triggered when GSP interrupt has been signalled
     Kernel::SharedPtr<Kernel::Event> interrupt_event;