Refactor SVC handler (#540)

* Refactor SVC handler

* Get rid of KernelErr

* Split kernel code files into multiple folders

Ryujinx.HLE/HOS/Kernel/Threading/KWritableEvent.cs

@@ -0,0 +1,24 @@
+using Ryujinx.HLE.HOS.Kernel.Common;
+
+namespace Ryujinx.HLE.HOS.Kernel.Threading
+{
+    class KWritableEvent
+    {
+        private KEvent _parent;
+
+        public KWritableEvent(KEvent parent)
+        {
+            _parent = parent;
+        }
+
+        public void Signal()
+        {
+            _parent.ReadableEvent.Signal();
+        }
+
+        public KernelResult Clear()
+        {
+            return _parent.ReadableEvent.Clear();
+        }
+    }
+}