[flang] [llvm] [flang][OpenMP]Add support for OpenMP ERROR directive (PR #119582)

[Mats Petersson via llvm-commits]

Leporacanthicus wrote:

> Looks good! Could you add checks for `-fdebug-dump-parse-tree-no-sema` as well to your testcase?

Done. I had to make a couple of minor changes to print the actual value of the AT and SEVERITY.

https://github.com/llvm/llvm-project/pull/119582