.module file not included

Problem/Motivation

If a module is enabled with no .module file created and then you create one the system will not detect it.

Steps to reproduce

Create a module with no .module file.
Enable the module.
Create the .module file and add a hook_theme for example.
Rebuild caches and the hook is never executed.

Proposed resolution

Allow creating a .module file after a module is enabled.

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet