Right now, the self-hosted code for ES6 modules uses methods and accessors installed on ModuleObject.prototype. All of these are self-hosted or C++-implemented functions, and ModuleObjects don't ever leak to content. What we should be doing for the methods at the very least is call them by their intrinsic names. E.g., `callFunction(module.getExportedNames, module)` would become `callFunction(ModuleGetExportedNames, module)`.