[project @ 1998-02-03 22:20:10 by sof]

Support for assertions:
  - if `assert' is not a variable name within
    scope, it is expanded to (GHCerr.assert__ <srcLoc>),

       GHCerr.assert__ :: String -> Bool -> a -> a

    where <srcLoc> encodes module name plus line number
    of the assertion.
  - enabled with -fglasgow-exts