[FAST486]

[FAST486]
FPU instructions never generate #UD. If CR0.EM is set, they generate #NM.
If there is no FPU and CR0.EM is cleared, they do nothing.
Add a helper macro FPU_ST for accessing FPU registers.
Add a compile-time option to disable the FPU.

svn path=/branches/ntvdm/; revision=61150