[clang] [Clang] Fixed an assertion in constant evaluation when using a defaulted comparison operator in a union (PR #198830)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-aarch64-darwin` running on `doug-worker-4` while building `clang` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/44703

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

```
Step 6 (test-build-unified-tree-check-all) failure: 1200 seconds without output running [b'ninja', b'check-all'], attempting to kill
...
llvm-lit: /Users/buildbot/buildbot-root/llvm-project/llvm/utils/lit/lit/llvm/config.py:569: note: using wasm-ld: /Volumes/RAMDisk/buildbot-root/aarch64-darwin/build/bin/wasm-ld
llvm-lit: /Users/buildbot/buildbot-root/llvm-project/llvm/utils/lit/lit/llvm/config.py:569: note: using ld.lld: /Volumes/RAMDisk/buildbot-root/aarch64-darwin/build/bin/ld.lld
llvm-lit: /Users/buildbot/buildbot-root/llvm-project/llvm/utils/lit/lit/llvm/config.py:569: note: using lld-link: /Volumes/RAMDisk/buildbot-root/aarch64-darwin/build/bin/lld-link
llvm-lit: /Users/buildbot/buildbot-root/llvm-project/llvm/utils/lit/lit/llvm/config.py:569: note: using ld64.lld: /Volumes/RAMDisk/buildbot-root/aarch64-darwin/build/bin/ld64.lld
llvm-lit: /Users/buildbot/buildbot-root/llvm-project/llvm/utils/lit/lit/llvm/config.py:569: note: using wasm-ld: /Volumes/RAMDisk/buildbot-root/aarch64-darwin/build/bin/wasm-ld
llvm-lit: /Users/buildbot/buildbot-root/llvm-project/llvm/utils/lit/lit/llvm/config.py:569: note: using ld.lld: /Volumes/RAMDisk/buildbot-root/aarch64-darwin/build/bin/ld.lld
llvm-lit: /Users/buildbot/buildbot-root/llvm-project/llvm/utils/lit/lit/llvm/config.py:569: note: using lld-link: /Volumes/RAMDisk/buildbot-root/aarch64-darwin/build/bin/lld-link
llvm-lit: /Users/buildbot/buildbot-root/llvm-project/llvm/utils/lit/lit/llvm/config.py:569: note: using ld64.lld: /Volumes/RAMDisk/buildbot-root/aarch64-darwin/build/bin/ld64.lld
llvm-lit: /Users/buildbot/buildbot-root/llvm-project/llvm/utils/lit/lit/llvm/config.py:569: note: using wasm-ld: /Volumes/RAMDisk/buildbot-root/aarch64-darwin/build/bin/wasm-ld
-- Testing: 94378 tests, 12 workers --
command timed out: 1200 seconds without output running [b'ninja', b'check-all'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=1241.544909

```

</details>

https://github.com/llvm/llvm-project/pull/198830