patch applied (ghc): External Core: don't print superfluous parens in case types

[Tim Chevalier]

Sat Mar 29 12:46:29 PDT 2008  Tim Chevalier <chevalier at alum.wellesley.edu>
  * External Core: don't print superfluous parens in case types
  
  The External Core printer was parenthesizing the scrutinee type in case expressions. Since this type is required to be atomic, the parens aren't necessary.

    M ./compiler/coreSyn/PprExternalCore.lhs -1 +1