Recent Sparc breakage

[Simon Marlow]

Sparc users in particular:  I've identified some recent breakage in the
Sparc port of GHC.  If you've been experiencing crashes in binaries
generated by a compiler built from recent (at least February) sources, then
I've checked in a fix which might help.

George, Marc: this probably fixes to the bugs you've both reported.  The
anon cvs repository should be updated around 1700 GMT today with the fix
included (look for an update to fptools/ghc/rts/StgCRun.c).

Cheers,
        Simon