Circular module graphs instantiate too early #2629
@jonco3 found this in https://bugzilla.mozilla.org/show_bug.cgi?id=1361988. Given the module graph
it appears we instantiate subgraphs too early, causing assertion failures in HostResolveImportedModule.
We probably need to move all instantiation to the "top level", instead of doing it on subgraphs as we go.