TODO

   1 - optimize FPU operations (evaluate x87 stack pointer statically) and
   2   fix cr0.TS emulation
   3 - fix CCOP optimisation
   4 - fix all remaining thread lock issues (must put TBs in a specific invalid
   5   state, find a solution for tb_flush()).
   6 - cpu loop optimisation (optimise ret case as the cpu state does not change)
   7 - fix arm fpu rounding (at least for float->integer conversions)
   8 - add IPC syscalls
   9
  10 lower priority:
  11 --------------
  12 - sysenter/sysexit emulation
  13 - SMP support
  14 - finish segment ops (call far, ret far, load_seg suppressed)
  15 - use -msoft-float on ARM
  16 - use kernel traps for unaligned accesses on ARM ?
  17 - handle rare page fault cases (in particular if page fault in heplers or
  18   in syscall emulation code).
  19 - fix thread stack freeing (use kernel 2.5.x CLONE_CHILD_CLEARTID)
  20 - more syscalls (in particular all 64 bit ones, IPCs, fix 64 bit
  21   issues, fix 16 bit uid issues)
  22 - use page_unprotect_range in every suitable syscall to handle all
  23   cases of self modifying code.
  24 - use gcc as a backend to generate better code (easy to do by using
  25   op-i386.c operations as local inline functions).
  26 - add SSE2/MMX operations