[flang] [llvm] [flang] implement `split` for fortran 2023 (PR #161484)

[Tom Eccles via llvm-commits]

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@@ -0,0 +1,43 @@
+! RUN: bbc -emit-fir -hlfir=false %s -o - | FileCheck %s
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tblah wrote:

Please could you add tests for dynamically optional values for BACK.

https://github.com/llvm/llvm-project/pull/161484