patch applied (ghc-6.6/ghc): Simplify desugaring of left sections

[Ian Lynagh]

Mon Sep 11 01:35:10 PDT 2006  simonpj at microsoft.com
  * Simplify desugaring of left sections
  
  	MERGE TO 6.6 branch!
  
  Some while ago I made the type checker a tiny bit more lenient about
  left sections, so that 
  	(x !)
  would typecheck iff
  	((!) x) 
  typechecks.  
  
  Strictly, Haskell 98 requires that the section typechecks iff
  	(\y. (!) x y)
  typechecks, and I should really have made the relaxation dependent on a 
  flag, but I didn't.
  
  Anyway, this commit fixes the *desugarer* so that it correctly desugars
  the programs that the typechecker passes.
  
  

    M ./compiler/deSugar/DsExpr.lhs -14 +4