Improve the reporting of module cycles, to give a nice message like this
[ghc-hetmet.git] / compiler / stgSyn /
drwxr-xr-x   ..
-rw-r--r-- 44055 CoreToStg.lhs
-rw-r--r-- 16230 StgLint.lhs
-rw-r--r-- 26334 StgSyn.lhs