patch applied (ghc): isDataTyCon should be False for all type families, even data type families

[Simon Peyton Jones]

Fri May  4 04:03:01 PDT 2007  simonpj at microsoft.com
  * isDataTyCon should be False for all type families, even data type families
  
  isDataTyCon advertises that it's true of "data types that are
  definitely represented by heap-allocated constructors.  These are
  srcutinised by Core-level @case@ expressions, and they get info tables
  allocated for them."
  
  Type-family TyCons never have this property, not even data type families.
  It's the *instance* TyCons that do.
  
  I hope that this change does not break anything that somehow relied
  on the old (wrong) semantics.

    M ./compiler/typecheck/TcGadt.lhs -20
    M ./compiler/types/TyCon.lhs -1 +6