[llvm] [TySan] A Type Sanitizer (LLVM) (PR #76259)

[Xi Ruoyao via llvm-commits]

xry111 wrote:

> Just rebased again on top of current `main`.
> 
> Would be great if we could get this in, as multiple people including @gbMattN and I think @tavianator would be interested in making improvements. As is, it is already useful (it catches a number of type-based alias violations in issues submitted by users https://discourse.llvm.org/t/reviving-typesanitizer-a-sanitizer-to-catch-type-based-aliasing-violations/66092/11) and having it in `main` would allow more people to improve the sanitizer more quickly

I guess you need to fix the build failures highlighted by the CI first:

```
FAILED: lib/Transforms/Instrumentation/CMakeFiles/LLVMInstrumentation.dir/TypeSanitizer.cpp.o 
/var/lib/buildkite-agent/builds/linux-56-59b8f5d88-5wwkv-1/llvm-project/github-pull-requests/llvm/lib/Transforms/Instrumentation/TypeSanitizer.cpp:40:10: fatal error: 'llvm/Transforms/Instrumentation.h' file not found
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```

It seems moved to `llvm/Transforms/Utils/Instrumentation.h` at 2ae968a0d9fb.

https://github.com/llvm/llvm-project/pull/76259