patch applied (ghc): Fixes to datacon wrappers for indexed data types

[Simon Peyton Jones]

Sun Apr 22 14:35:03 PDT 2007  simonpj at microsoft.com
  * Fixes to datacon wrappers for indexed data types
  
  nominolo at gmail.com pointed out (Trac #1204) that indexed data types
  aren't quite right. I investigated and found that the wrapper
  functions for indexed data types, generated in MkId, are really very
  confusing.  In particular, we'd like these combinations to work
  	newtype + indexed data type
  	GADT + indexted data type
  The wrapper situation gets a bit complicated!  
  
  I did a bit of refactoring, and improved matters, I think.  I am not
  certain that I have gotten it right yet, but I think it's better.
  I'm committing it now becuase it's been on my non-backed-up laptop for
  a month and I want to get it into the repo. I don't think I've broken
  anything, but I don't regard it as 'done'.
  

    M ./compiler/basicTypes/DataCon.lhs -28 +45
    M ./compiler/basicTypes/MkId.lhs -85 +122
    M ./compiler/main/PprTyThing.hs -11 +13
    M ./compiler/typecheck/TcPat.lhs -3 +3
    M ./compiler/typecheck/TcTyClsDecls.lhs -8 +8
    M ./compiler/typecheck/TcType.lhs -3 +3
    M ./compiler/types/TyCon.lhs -8 +10
    M ./compiler/types/Unify.lhs -4 +21