file_sys: Add class to manage game patches

Right now only includes Updates, but should eventually contain all of the other patches we need.

src/core/file_sys/patch_manager.h

@@ -0,0 +1,42 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <map>
+#include "common/common_types.h"
+#include "core/file_sys/vfs.h"
+
+namespace FileSys {
+
+std::string FormatTitleVersion(u32 version, bool full = false);
+
+enum class PatchType {
+    Update,
+};
+
+std::string FormatPatchTypeName(PatchType type);
+
+// A centralized class to manage patches to games.
+class PatchManager {
+public:
+    explicit PatchManager(u64 title_id);
+
+    // Currently tracked ExeFS patches:
+    // - Game Updates
+    VirtualDir PatchExeFS(VirtualDir exefs) const;
+
+    // Currently tracked RomFS patches:
+    // - Game Updates
+    VirtualFile PatchRomFS(VirtualFile romfs) const;
+
+    // Returns a vector of pairs between patch names and patch versions.
+    // i.e. Update v80 will return {Update, 80}
+    std::map<PatchType, u32> GetPatchVersionNames() const;
+
+private:
+    u64 title_id;
+};
+
+} // namespace FileSys