ToExtended method
Implementation
void ToExtended(ExtendedGroupElement r) {
FieldElement t = new FieldElement();
FieldElement recip = new FieldElement();
FeInvert(recip, Z);
FeMul(t, X, Y);
FeCopy(r.X, X);
FeCopy(r.Y, Y);
FeCopy(r.Z, Z);
FeMul(r.T, t, recip);
}