[llvm-branch-commits] [flang] release/21.x: [Flang] Fix ASSIGN statement (#149941) (PR #150228)

[Tom Eccles via llvm-branch-commits]

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

LGTM. This is a low risk bug fix preventing a crash in flang.

https://github.com/llvm/llvm-project/pull/150228