patch applied (ghc): Loosen the conditions for -XUndecidableInstances; fixes Trac #4200

[Simon Peyton Jones]

Sun Sep 19 09:26:23 PDT 2010  simonpj at microsoft.com
  * Loosen the conditions for -XUndecidableInstances; fixes Trac #4200

    M ./compiler/typecheck/TcMType.lhs -8 +6

View patch online:
http://darcs.haskell.org/cgi-bin/darcsweb.cgi?r=ghc;a=darcs_commitdiff;h=20100919162623-1287e-7440fab726cff34353edda524fec2068a2e6fa4c.gz