Reduce manually duplicated code in random with deftransform for random

Describe the bug

The deftransform for random (in float-tran.lisp) has an optimization for returning random integers less than 2^{32}. However, the function random (in rand-xoroshiro.lisp duplicates this optimization.

This makes the code somewhat fragile if the deftransform is modified but the function isn't (and vice versa). We can make this consistent by just doing (random arg state) in random. Then we are always consistent.

This, however, depends on the compiler being able to apply the deftransform. Some simple testing shows that this is the case.

Reducing this duplication is useful.

Also note that rand-mt19937.lisp does exactly this.

Desktop (please complete the following information):

• OS: All