Issue 739 fix seg fault

[vehre]

coverage on master

Summary of changes

Fix a crash when indexing into static array.

Rationale for changes

Prevent a segfault.

Additional info and certifications

This pull request (PR) is a:

• [x] Bug fix
• [ ] Feature addition
• [ ] Other, Please describe:

I certify that

• [x] I certify that:
  • I have reviewed and followed the contributing guidelines
  • I will wait at least 24 hours before self-approving the PR to give another OpenCoarrays developer a chance to review my proposed code
  • I have not introduced errant white space (no trailing white space or white space errors may be introduced)
  • I have added an explanation of what these changes do and why they should be included
  • I have checked to ensure there aren't other open Pull Requests for the same change
  • I have you written new tests for these changes
  • I have successfully tested these changes locally
  • I have commented any non-trivial, non-obvious code changes
  • The commits are logically atomic, self consistent and coherent
  • The commit messages follow best practices
  • Test coverage is maintained or increased after this is merged

Code coverage data

[rouson]

@everythingfunctional could you take a look at what's happening with the "pullapprove Failed to load extends URL (HTTP 404)" message above?

[everythingfunctional]

I've not seen the WIP or pullapprove checks before, and I don't see anything in the code in the repository that would indicate enabling them. Is there some GitHub setting/new feature that got turned on?

[rouson]

@everythingfunctional thanks for checking. I found an email indicating that this is third-party app. I don't recall enabling, but I think I have now disabled it. I also replied to the email to ask how to remove it from this PR. I also tried merging into main at the command line, but my subsequent push was rejected.