[clang] default clause replaced by otherwise clause for metadirective in OpenMP 5.2 (PR #125648)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-aarch64-quick` running on `linaro-clang-aarch64-quick` while building `clang` at step 5 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/65/builds/12602

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (ninja check 1) failure: stage 1 checked (failure)
******************** TEST 'Clang :: OpenMP/metadirective_messages.cpp' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /home/tcwg-buildbot/worker/clang-aarch64-quick/stage1/bin/clang -cc1 -internal-isystem /home/tcwg-buildbot/worker/clang-aarch64-quick/stage1/lib/clang/21/include -nostdsysteminc -triple=x86_64-pc-linux-gnu -verify -fopenmp -x c++ -std=c++14 -fexceptions -fcxx-exceptions /home/tcwg-buildbot/worker/clang-aarch64-quick/llvm/clang/test/OpenMP/metadirective_messages.cpp
+ /home/tcwg-buildbot/worker/clang-aarch64-quick/stage1/bin/clang -cc1 -internal-isystem /home/tcwg-buildbot/worker/clang-aarch64-quick/stage1/lib/clang/21/include -nostdsysteminc -triple=x86_64-pc-linux-gnu -verify -fopenmp -x c++ -std=c++14 -fexceptions -fcxx-exceptions /home/tcwg-buildbot/worker/clang-aarch64-quick/llvm/clang/test/OpenMP/metadirective_messages.cpp
RUN: at line 3: /home/tcwg-buildbot/worker/clang-aarch64-quick/stage1/bin/clang -cc1 -internal-isystem /home/tcwg-buildbot/worker/clang-aarch64-quick/stage1/lib/clang/21/include -nostdsysteminc -triple=x86_64-pc-linux-gnu -verify -fopenmp-simd -x c++ -std=c++14 -fexceptions -fcxx-exceptions /home/tcwg-buildbot/worker/clang-aarch64-quick/llvm/clang/test/OpenMP/metadirective_messages.cpp
+ /home/tcwg-buildbot/worker/clang-aarch64-quick/stage1/bin/clang -cc1 -internal-isystem /home/tcwg-buildbot/worker/clang-aarch64-quick/stage1/lib/clang/21/include -nostdsysteminc -triple=x86_64-pc-linux-gnu -verify -fopenmp-simd -x c++ -std=c++14 -fexceptions -fcxx-exceptions /home/tcwg-buildbot/worker/clang-aarch64-quick/llvm/clang/test/OpenMP/metadirective_messages.cpp
RUN: at line 5: /home/tcwg-buildbot/worker/clang-aarch64-quick/stage1/bin/clang -cc1 -internal-isystem /home/tcwg-buildbot/worker/clang-aarch64-quick/stage1/lib/clang/21/include -nostdsysteminc -verify=expected,omp52 -fopenmp -fopenmp-version=52 -ferror-limit 100 -o - /home/tcwg-buildbot/worker/clang-aarch64-quick/llvm/clang/test/OpenMP/metadirective_messages.cpp -Wuninitialized
+ /home/tcwg-buildbot/worker/clang-aarch64-quick/stage1/bin/clang -cc1 -internal-isystem /home/tcwg-buildbot/worker/clang-aarch64-quick/stage1/lib/clang/21/include -nostdsysteminc -verify=expected,omp52 -fopenmp -fopenmp-version=52 -ferror-limit 100 -o - /home/tcwg-buildbot/worker/clang-aarch64-quick/llvm/clang/test/OpenMP/metadirective_messages.cpp -Wuninitialized
error: 'expected-warning' diagnostics expected but not seen: 
  File /home/tcwg-buildbot/worker/clang-aarch64-quick/llvm/clang/test/OpenMP/metadirective_messages.cpp Line 23: isa trait 'some-unsupported-feature' is not known to the current target; verify the spelling or consider restricting the context selector with the 'arch' selector further
1 error generated.

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/125648