[patch] PR 35940 Array BACK ignored in INDEX intrinsic when other args scalar

[Jerry DeLisle]

Bud Davis wrote:
> The expression was being simplified when it should not have been.  Corrected by checking for a
> constant argument in do_simplify.
> 
> The below test case fails prior to application of the patch and passes after.  The test case is
> the submitters code, with a bit of editing.
> 
> Tested i686/gnu linux with no new regressions.
> 
OK to commit.

Jerry