Method append

src/platforms/wasm/fs_wasm.cpp.hpp:79–83

    FileData() = default;

    void append(const u8 *data, size_t len) {
        fl::unique_lock<fl::mutex> lock(mMutex);
        mData.insert(mData.end(), data, data + len);
        mCapacity = fl::max(mCapacity, mData.size());
    }

    size_t read(size_t pos, u8 *dst, size_t len) {
        fl::unique_lock<fl::mutex> lock(mMutex);