fs: Add missing types and fix compilation problems

src/core/file_sys/fs_common.h

@@ -0,0 +1,38 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "common/common_funcs.h"
+
+namespace FileSys {
+
+struct Int64 {
+    u32 low;
+    u32 high;
+
+    constexpr void Set(s64 v) {
+        this->low = static_cast<u32>((v & static_cast<u64>(0x00000000FFFFFFFFULL)) >> 0);
+        this->high = static_cast<u32>((v & static_cast<u64>(0xFFFFFFFF00000000ULL)) >> 32);
+    }
+
+    constexpr s64 Get() const {
+        return (static_cast<s64>(this->high) << 32) | (static_cast<s64>(this->low));
+    }
+
+    constexpr Int64& operator=(s64 v) {
+        this->Set(v);
+        return *this;
+    }
+
+    constexpr operator s64() const {
+        return this->Get();
+    }
+};
+
+constexpr inline size_t IntegrityMinLayerCount = 2;
+constexpr inline size_t IntegrityMaxLayerCount = 7;
+constexpr inline size_t IntegrityLayerCountSave = 5;
+constexpr inline size_t IntegrityLayerCountSaveDataMeta = 4;
+
+} // namespace FileSys