[clang] [flang] [llvm] [mlir] [Flang]Fix for changed code at the end of AllocaIP. (PR #92430)

[Tom Eccles via cfe-commits]

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

LGTM if @Meinersbur is happy. It's a shame about the fallout to the clang tests but I can see that would be very difficult to avoid.

Thank you for persisting with this difficult patch.

https://github.com/llvm/llvm-project/pull/92430