Explicitly instantiate constructors/destructors for Kernel objects

This should speed up compile times a bit, as well as enable more liberal
use of forward declarations. (Due to SharedPtr not trying to emit the
destructor anymore.)

src/core/hle/kernel/session.cpp

@@ -0,0 +1,13 @@
+// Copyright 2015 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/hle/kernel/session.h"
+#include "core/hle/kernel/thread.h"
+
+namespace Kernel {
+
+Session::Session() {}
+Session::~Session() {}
+
+}