[initialize derived instance indicator
John Meacham <john@repetae.net>**20061107025955] hunk ./FrontEnd/Class.hs 69
-emptyInstance = Inst { instSrcLoc = bogusASrcLoc, instHead = error "emptyInstance", instAssocs = [] }
+emptyInstance = Inst { instDerived = False, instSrcLoc = bogusASrcLoc, instHead = error "emptyInstance", instAssocs = [] }