Implement FIFO semaphore (#1286)

* Implement FIFO semaphore

* New enum for FIFO semaphore operation

Ryujinx.Graphics.Gpu/State/SemaphoreOperation.cs

@@ -0,0 +1,12 @@
+namespace Ryujinx.Graphics.Gpu.State
+{
+    /// <summary>
+    /// GPU semaphore operation.
+    /// </summary>
+    enum SemaphoreOperation
+    {
+        Release = 0,
+        Acquire = 1,
+        Counter = 2
+    }
+}