patch applied (ghc): x86_64 NCG: fix register usage for CALLs

[Wolfgang Thaller]

Tue Nov 28 17:34:29 PST 2006  wolfgang.thaller at gmx.net
  * x86_64 NCG: fix register usage for CALLs
  
  For varargs calls, CALL reads the %al register; record that fact for the benefit of the
  register allocator.
  (There was a previous attempt to do this, but it was broken.)
  

    M ./compiler/nativeGen/MachCodeGen.hs -1 +1
    M ./compiler/nativeGen/RegAllocInfo.hs -6