Re-enable deftransform for random integers
## Describe the bug
We have a [`deftransform` for word-sized random
integers](src/compiler/float-tran.lisp#L279). This was used for the
MT19937 generator. I think we forgot about this when we implemented
the xoroshiro generator.
We can see this if we place this code in a file and compile it to
produce a trace file:
```
(defun zot ()
(random 100000))
```
## To Reproduce
Steps to reproduce the behavior:
1. Compile the above code with `:trace-file t`
2. Look at the trace file. You can see a call to `truncate`.
## Expected behavior
We should be doing a multiply instead of a truncate. Note also that
this is a bug in that `random` uses a
[multiplication](src/code/rand-xoroshiro.lisp#L493). We need to be
consistent between the two code paths. I guess in practice, this is
not so easy to see, but we could probably create a simple test for
this.
## Desktop (please complete the following information):
- OS: All
- Version: Any version after xoroshiro was implemented.
issue