This patch fixes up some lose ends left over from the last x86-64 jumbo merge.

 - make it compile again. ia32_ioctl was referencing IDE ioctls that got
   remove in a merge race
 - Use the memset/FXRSTOR way to initialize the FPU, as discussed.
 - Fix semctl/shmctl ABI (thanks to Andreas Schwab)
 - Other minor fixes.