[compiler-rt] [tsan] Fix running check-ubsan with COMPILER_RT_DEBUG=ON (PR #83890)

[Fangrui Song via llvm-commits]

https://github.com/MaskRay approved this pull request.

I prefer this to the alternative that changes the interceptor order.

`tls_model("initial-exec")` will make the code not suitable when the runtime is dlopened, which can be ignored for this use case. In addition, this is for COMPILER_RT_DEBUG=ON, a debugging feature.

https://github.com/llvm/llvm-project/pull/83890