patch applied (ghc): FIX #1679: crash on returning from a foreign call

[Simon Marlow]

Thu Nov 15 05:16:35 PST 2007  Simon Marlow <simonmar at microsoft.com>
  * FIX #1679: crash on returning from a foreign call
  We forgot to save a pointer to the BCO over the foreign call.  Doing
  enough allocation and GC during the call could provoke a crash.

    M ./rts/Interpreter.c -1 +16