Properly initialize MXCSR and XMM registers if we only write the x87 FPU state and the process has not used the FPU yet.
Properly initialize MXCSR and XMM registers if we only write the x87 FPU state
and the process has not used the FPU yet.

ok guenther@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars