core/debugger: Implement new GDB stub debugger

src/core/debugger/debugger.h

@@ -0,0 +1,46 @@
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <memory>
+
+#include "common/common_types.h"
+
+namespace Kernel {
+class KThread;
+}
+
+namespace Core {
+class System;
+
+class DebuggerImpl;
+
+class Debugger {
+public:
+    /**
+     * Blocks and waits for a connection on localhost, port `server_port`.
+     * Does not create the debugger if the port is already in use.
+     */
+    explicit Debugger(Core::System& system, u16 server_port);
+    ~Debugger();
+
+    /**
+     * Notify the debugger that the given thread is stopped
+     * (due to a breakpoint, or due to stopping after a successful step).
+     *
+     * The debugger will asynchronously halt emulation after the notification has
+     * occurred. If another thread attempts to notify before emulation has stopped,
+     * it is ignored and this method will return false. Otherwise it will return true.
+     */
+    bool NotifyThreadStopped(Kernel::KThread* thread);
+
+    /**
+     * Returns whether a step is in progress.
+     */
+    bool IsStepping() const;
+
+private:
+    std::unique_ptr<DebuggerImpl> impl;
+};
+} // namespace Core