E2005 'int64' is not a type identifier

게시판에 올라온 예제를 보고 테스트를 하는 중인데...

function GetFileSize64(const FileName: string): int64; //LONGLONG;
var
    FileHandle: LongWord;
    HiSize, LoSize: LongWord;
begin
    Result := -1;
    FileHandle := CreateFile( PChar(FileName), GENERIC_READ , FILE_SHARE_READ
                            , nil            , OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
    LoSize := GetFileSize(FileHandle, @HiSize);
    CloseHandle(FileHandle);

    if (LoSize = $FFFFFFFF) and (GetLastError <> NO_ERROR) then
        Exit; // Raised Error

    Result := LoSize + (HiSize shl 32);
end;

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