bug#29866: 27.0.50; cl-loop: Calculate the array length just once

[Drew Adams]

> While studying this code I found easier to hack if we use gensym's
> instead of make-symbol; otherwise, the code creates several symbols with
> the same printed representation "--cl-var--".  For example, with
> current code you can read expansions with something like:
> 
> (let* ((--cl-var-- 'foo)
>        (--cl-var-- 'bar))

That's the same variable, `--cl-var--', bound
first to `foo' and then to `bar'.

> I prefer to read:
> 
> (let* ((--cl-var--1 'foo)
>        (--cl-var--2 'bar))

That's two different variables.

> Do you have any preference in these cases?

As presented here, they are not equivalent.
Check the actual code to see if the second
can, in fact, be used in place of the first.