patch applied (ghc): Fix apparently-long-standing bug in FloatIn

[Simon Peyton Jones]

Wed Jan 10 03:13:44 PST 2007  simonpj at microsoft.com
  * Fix apparently-long-standing bug in FloatIn
  
  The float-in pass wasn't doing the right thing when you have
  
  	let x{rule mentions y} = rhs in body
  
  It allowed a binding mentioning y to float into the body, which is
  obviously wrong.  I think this bug has been there a long time; I don't
  really know why it has not come up before.
  
  It showed up when compiling Text.Regex.Base.Context with WAY=p in
  package regex-base.
  

    M ./compiler/simplCore/FloatIn.lhs -30 +47