Correctness issues:

- rework eflags optimization (will be a consequence of TCG port)
- SVM: rework the implementation: simplify code, move most intercept
  tests as dynamic, correct segment access, verify exception safety,
  cpu save/restore, SMM save/restore. 
- arpl eflags computation is invalid
- x86_64: fxsave/fxrestore intel/amd differences
- x86_64: lcall/ljmp intel/amd differences ?
- x86_64: cmpxchgl intel/amd differences ?
- x86_64: cmovl intel/amd differences ?
- cmpxchg16b + cmpxchg8b cpuid test
- x86: monitor invalid 
- better code fetch (different exception handling + CS.limit support)
- user/kernel PUSHL/POPL in helper.c
- add missing cpuid tests
- return UD exception if LOCK prefix incorrectly used
- test ldt limit < 7 ?
- fix some 16 bit sp push/pop overflow (pusha/popa, lcall lret)
- full support of segment limit/rights 
- full x87 exception support
- improve x87 bit exactness (use bochs code ?)
- DRx register support
- CR0.AC emulation
- SSE alignment checks
- fix SSE min/max with nans

Optimizations/Features:

- finish TCG port
- add SVM nested paging support
- add VMX support
- add AVX support
- add SSE5 support
- evaluate x87 stack pointer statically
- find a way to avoid translating several time the same TB if CR0.TS
  is set or not.
- move kqemu support outside target-i386.