[Yhc] Fixes for issue 110 and 139

[Stephan Hoermann]

Hi,
I have uploaded patches for issues 110 
(http://code.google.com/p/yhc/issues/detail?id=110) and 139 
(http://code.google.com/p/yhc/issues/detail?id=139). Can someone please 
check them.

For issue 139 I heavily borrowed from the GHC code to implement some of 
the primitive functions for Floats and Doubles. Is that ok?

Also can someone please explain to me how multiplication for floats and 
doubles is done. I can see the call to primIntMul for Integers but I 
haven't found anything for floats and doubles.

Regards,
Stephan Hoermann