* Add FSTCW/FNSTCW operator for x86 assembler (Store x87 FPU Control Word)
* Add FSTSW/FNSTSW operator for x86 assembler (Store x87 FPU Status Word)
* Fix some issues of float instructions for x86 assembler.
* Add FSAVE/FNSAVE operator for x86 assembler (Store x87 FPU State)