> Right, I think at least on MS-Windows we need to do that.  On Posix
> platforms, Emacs will be able to start if there's no libgccjit (and
> will crash if it attempts to call any of its functions), so it might
> be a good idea to use dlopen/dlsym there as well.  But on Windows it
> is IMO critical.

The attached patch does implement dynamic loading of libgccjit in Windows.