Add Yuzu's file system implementation, will make it compilable later

core/fs/ips_layer.h

@@ -0,0 +1,43 @@
+// SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <array>
+#include <memory>
+#include <vector>
+
+#include "common/common_types.h"
+#include "core/file_sys/vfs/vfs.h"
+
+namespace FileSys {
+
+VirtualFile PatchIPS(const VirtualFile& in, const VirtualFile& ips);
+
+class IPSwitchCompiler {
+public:
+    explicit IPSwitchCompiler(VirtualFile patch_text);
+    ~IPSwitchCompiler();
+
+    std::array<u8, 0x20> GetBuildID() const;
+    bool IsValid() const;
+    VirtualFile Apply(const VirtualFile& in) const;
+
+private:
+    struct IPSwitchPatch;
+
+    void ParseFlag(const std::string& flag);
+    void Parse();
+
+    bool valid = false;
+
+    VirtualFile patch_text;
+    std::vector<IPSwitchPatch> patches;
+    std::array<u8, 0x20> nso_build_id{};
+    bool is_little_endian = false;
+    s64 offset_shift = 0;
+    bool print_values = false;
+    std::string last_comment = "";
+};
+
+} // namespace FileSys