* Add properties to ModuleFile which holds information from the control
block.
* 'ExtendedValidationInfo' parameter for 'ModuleFileSharedCore::load()'
cannot be 'nullptr'. Make it non-defaulted Rvalue reference.
The difference with `ModuleFile` is that `ModuleFileSharedCore` provides immutable data and is independent of a particular ASTContext.
It is designed to be able to be shared across multiple `ModuleFile`s of different `ASTContext`s in a thread-safe manner.