Kernel: Correct behavior of Condition Variables to be more similar to real hardware.

This commit ensures cond var threads act exactly as they do in the real
console. The original implementation uses an RBTree and the behavior of
cond var threads is that at the same priority level they act like a
FIFO.

src/core/hle/kernel/thread.cpp

@@ -306,8 +306,16 @@ void Thread::UpdatePriority() {
         return;
     }
 
+    if (GetStatus() == ThreadStatus::WaitCondVar) {
+        owner_process->RemoveConditionVariableThread(this);
+    }
+
     SetCurrentPriority(new_priority);
 
+    if (GetStatus() == ThreadStatus::WaitCondVar) {
+        owner_process->InsertConditionVariableThread(this);
+    }
+
     if (!lock_owner) {
         return;
     }