Common: Implement a basic SpinLock class

src/common/spin_lock.h

@@ -0,0 +1,20 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <atomic>
+
+namespace Common {
+
+class SpinLock {
+public:
+    void lock();
+    void unlock();
+
+private:
+    std::atomic_flag lck = ATOMIC_FLAG_INIT;
+};
+
+} // namespace Common