[flang-commits] [flang] [Flang] Fix a crash when equivalence and namelist statements are used (PR #150081)

[Tom Eccles via flang-commits]

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

LGTM, thanks. Please backport this to LLVM 21 if possible.

https://github.com/llvm/llvm-project/pull/150081