patch applied (ghc-6.8/ghc): we need to #include "Stg.h" first, we can't rely on GHC to inject it

[Ian Lynagh]

Wed Oct 10 08:32:44 PDT 2007  Simon Marlow <simonmar at microsoft.com>
  * we need to #include "Stg.h" first, we can't rely on GHC to inject it
  This fixes the unreg build, and in general building the RTS code
  via-C. I'm not sure at what stage this was broken, but I think it
  was working accidentally before.

    M ./rts/HCIncludes.h +1