Optimizations to many vops to allow a descriptor for the second arg.
* Allow the second arg to be a descriptor for the basic arithmetic operations on single floats and double floats. Previously, the boxed number would be loaded to a temporary reg for the operation. This saves the load and the extra register. * Allow a descriptor for the second arg in the comparison vops, the float conversion vops and the float truncation vops. * Allow descriptor for sqrt vop.