Correctness issues:

- some eflags manipulation incorrectly reset the bit 0x2.

- SVM: test, cpu save/restore, SMM save/restore. 

- x86_64: lcall/ljmp intel/amd differences ?

- 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:

- add SVM nested paging support

- add VMX support

- add AVX support

- add SSE5 support

- fxsave/fxrstor AMD extensions

- improve monitor/mwait support

- faster EFLAGS update: consider SZAP, C, O can be updated separately

  with a bit field in CC_OP and more state variables.

- 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.