[cvs-nhc98] patch applied (hat): Fix import/hiding/re-export bug + formatting tidy-up.

[Malcolm Wallace]

Thu Mar 22 10:34:28 PST 2001  malcolm
  * Fix import/hiding/re-export bug + formatting tidy-up.
    Compiling the following module:
        module B (x) where
        import A hiding (x)
        import qualified A
        x = ... A.x ...
    led to an incorrect interface file, where both B.x and A.x were exported.

    M ./src/compiler98/PreImport.hs -66 +95