Fix warning variable length arrays in C++ are a Clang extension

[marchdf]

Don't look until #7 is merged.

[marchdf]

Ok you can look now.

[marchdf]

@mbkuhn are allocate_plan_copy functions ever used? I can't find anywhere in amr-wind (or anywhere on github for that matter) where they are used. Maybe in a private repo in some other thing? If they aren't used, then I might just delete them. If they are used... I am going to have to change their interface because the out will need to be returned as well.

[marchdf]

Brief comment: variable length arrays are fine C99 but they are not in the C++ standard.

[mbkuhn]

@mbkuhn are allocate_plan_copy functions ever used? I can't find anywhere in amr-wind (or anywhere on github for that matter) where they are used. Maybe in a private repo in some other thing? If they aren't used, then I might just delete them. If they are used... I am going to have to change their interface because the out will need to be returned as well.

Good question. I set them up as I was developing and testing the repo, but then I think I didn't end up needing them / they weren't a good fit in the AMR-Wind interface. I think they still exist in the develop_test branch, but I can handle that myself. Feel free to remove.

[marchdf]

Cool, I removed them.

[marchdf]

I ran the tests and they pass. So I think we can merge.