patch applied (ghc): use " lock cmpxchg" instead of " lock/cmpxchg"

[Ian Lynagh]

Fri Nov 17 03:44:29 PST 2006  Simon Marlow <simonmar at microsoft.com>
  * use "lock cmpxchg" instead of "lock/cmpxchg"
  I'm not sure where the latter version came from, but it apparently
  doesn't generate a legal instruction on Solaris.

    M ./includes/SMP.h -1 +1