Reachable modules from DynFlags out of date

[Jan Stolarek]

> I suspect you need to add all of
I believe Simon needs to figure out the diff, ie. which modules are displayed in the dependency 
list but are missing in the compiler/ghc.mk file. I recall I had to done the same in one of my 
commits:

https://github.com/jstolarek/ghc/commit/53948f915140396acd1b80c6a7a252b2d1e12635#diff-ba0ee6a425ab9ec6d7a2ef6c394ba455

Janek