patch applied (ghc): Check that lazy patterns are for lifted types

[Simon Peyton Jones]

Tue Aug  8 06:59:10 PDT 2006  simonpj at microsoft.com
  * Check that lazy patterns are for lifted types
  
  A lazy pattern match must be for a lifted type. This is illegal:
  
  	f x = case g x of 
                  ~(# x,y #) -> ...
  
  This commit fixes the problem.  Trac #845, test is tcfail159
   

    M ./compiler/typecheck/TcPat.lhs -1 +7