Update to Replacement GMP page

[Peter Tanski]

Hello all,

I made another update to the notes on Replacing GMP, at http:// 
hackage.haskell.org/trac/ghc/wiki/ReplacingGMPNotes .  It's pretty  
basic and you'd probably find it shabby, but comments, modifications  
appreciated.  I am still in the throes of trying to *portably* beat  
GMP for speed and accuracy.  (The portability problem comes in when I  
may no longer rely on Altivec/SSE/3DNow! support on other processors  
and need to optimise in pure C.)

-Pete