Implementation, for TCG, of the specifications provided in Intel and AMD
programmer's manuals regarding the x87 exception pointers. That is, when
executing instructions fstenv/fnstenv, fsave and fxsave the values for
the instruction pointer, data pointer and opcode of the last non-control
x87 instruction executed, are correctly saved to the specified memory
address. When executing instructions fldenv, frstor and fxrstor the
values that are going to be considered the instruction pointer, data
pointer and opcode of the last non-control x87 instruction are obtained
from the specified memory address.