Sounds like an idea for custom extension, but I doubt this would work
as a general approach.
It limits dynamic nature of php, so won't be suitable for all cases
Did you see this extension?
http://pecl.php.net/package/automap
Just two points:
1) It doesn't need to be suitable for all cases, as you can still require/include or autoload your file exactly as today. It's an addition, not a replacement.
2) It doesn't limit the dynamic nature of PHP as those files can be generated from a script just as any text file, and will be used for large redistributable libraries, frameworks, which are more static in nature than the application code utilising them.
As for the extension, I'll check it out, thanks.
Regards, Stan Vassilev