x86: handle more tricky instructions.

- support undocumented instructions FSTP & FSTPNCE. see http://blogs.technet.com/b/mmpc/archive/2013/06/24/investigation-of-a-new-undocumented-instruction-trick.aspx
- TEST instructions with opcode 0xF6, 0xF7 (MRM1r)
10 files changed