Comment # 15 on bug 8 from Johannes Pfau

OK, here's the fix for current GDC:
https://github.com/jpf91/GDC/commits/fixOrder

GDC/frontend changes
https://github.com/jpf91/GDC/commit/5bc609b3fdc42d8df46118ed19ac8b582fe47040

Druntime changes
https://github.com/jpf91/GDC/commit/3517843d79e7259b91f160404448423c26395e79

Changes to old tests + new tests:
https://github.com/jpf91/GDC/commit/161e2dd60414226bbb6e8209816c76f525d581dd

The next steps are:
* Porting this to dmd, then asking the dmd maintainers to adapt their backend
to evaluate extern(C) functions and assignments LTR.
* Waiting till the 2.065 frontend has been merged into GDC
* Then backport these changes to GDC