[llvm] [Flang-rt] Implement same behavior as -O3 for zero-length arrays (PR #171480)

[Peter Klausler via llvm-commits]

https://github.com/klausler approved this pull request.

Approved, and please ignore Copilot's request to make the error message confusing.

https://github.com/llvm/llvm-project/pull/171480