Patch extrq (#943)

* Use a singleton for instruction decoding

* Use singleton class

* Patch `EXTRQ`

* Fixup signal context functions

* Update CMakeLists.txt

---------

Co-authored-by: georgemoralis <giorgosmrls@gmail.com>

src/common/signal_context.h

@@ -0,0 +1,18 @@
+// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "common/types.h"
+
+namespace Common {
+
+void* GetXmmPointer(void* ctx, u8 index);
+
+void* GetRip(void* ctx);
+
+void IncrementRip(void* ctx, u64 length);
+
+bool IsWriteError(void* ctx);
+
+} // namespace Common