[libcxx-commits] [libcxx] Revert "[libc++] Optimize copy construction and assignment of __tree" (PR #152180)

[Vitaly Buka via libcxx-commits]

vitalybuka wrote:

> #152181 should fix the issue. I'd really like to know why this wasn't caught in the CI though. Is there some special flag required to check for this kind of stuff?

I believe CI has check-cxx with ubsan, our bot has "check-cxx with ubsan" and it does not fail.

What fails is using libcxx to compile llvm, type from report is 
```
std::map<std::string, std::unique_ptr<ACLEIntrinsic>> ACLEIntrinsics;
```

So I guess libcxx lack of test coverage for them?

https://github.com/llvm/llvm-project/pull/152180