ghc-7.6 updates
Merge pull request #1 from michaelt/master

ghc-7.6 updates

Many thanks for taking the trouble to do this! Your changes look fine, the problem is actually in my code: it turns out the test suite doesn't work in a clean repo. The preprocessor doesn't chase imports, so you have to manually run it on imported files before they will be visible to the typechecker, and the test suite doesn't do this. If you load examples/Cost.hs and examples/Vectors.hs in GHCi (thereby invoking inch and generating the necessary files) then the tests should pass. I'll try to come up with a better solution, or at least fix the test suite...