Remove tests that fail on 32 bit

I wasn't able to determine what's happening here; the commented out tests fail _only_ on 32 bit systems and _only_ if compiled with `-O`. What's even stranger is that `ghc -O` produces _exactly the same_ core on 32 and 64 bit, but it fails only of 32 bit.

This looks suspiciously like a GHC bug (since optimized build produces different results from non-optimized). I will investigate this more and file a GHC bug if this is the case, but I suggest removing these test cases meanwhile.