patch applied (ghc): Decouple -O from -fvia-C

[Wolfgang Thaller]

Fri Dec  1 04:53:04 PST 2006  wolfgang.thaller at gmx.net
  * Decouple -O from -fvia-C
  
  Nowadays, there are situations where -fvia-C is definitely unwanted, such
  as when -fPIC is used on some platforms, so we do not want implicit -fvia-C
  any more.

    M ./compiler/main/DynFlags.hs -3 +1
    M ./docs/users_guide/phases.xml -6 +3
    M ./docs/users_guide/sooner.xml -3
    M ./docs/users_guide/using.xml -4