InvalidateRgn method
Implementation
int InvalidateRgn(
  ffi.Pointer<HWND__> hWnd,
  ffi.Pointer<HRGN__> hRgn,
  int bErase,
) {
  return (_InvalidateRgn ??=
      _dylib.lookupFunction<_c_InvalidateRgn, _dart_InvalidateRgn>(
          'InvalidateRgn'))(
    hWnd,
    hRgn,
    bErase,
  );
}