class WinFFI::LARGE_INTEGER
msdn.microsoft.com/en-us/library/windows/desktop/aa383713(v=vs.85).aspx class LARGE_INTEGER_STRUCT < FFIAdditions::Struct
layout LowPart: :dword, HighPart: :long
end
class LARGE_INTEGER
< FFIAdditions::Union
layout s: LARGE_INTEGER_STRUCT, u: LARGE_INTEGER_STRUCT
end