patch applied (packages/base): Make Control.Exception buildable by nhc98.

[Malcolm Wallace]

Fri May  4 03:55:48 PDT 2007  Malcolm.Wallace at cs.york.ac.uk
  * Make Control.Exception buildable by nhc98.
  The nhc98 does not have true exceptions, but these additions should be
  enough infrastructure to pretend that it does.  Only IO exceptions will
  actually work.

    M ./Control/Exception.hs -6 +61
    M ./Makefile.nhc98 -1 +3