[compiler-rt] [compiler-rt][rtsan] Introduce first end to end RTsan lit tests, enable instrumented unit tests (PR #105732)

[Petr Hosek via llvm-commits]

petrhosek wrote:

> We don't install `libatomic` on our builders (which is a part of libgcc), instead we use `libclang_rt.atomic` that comes directly from compiler-rt. I think we need to update the following logic to properly handle both `libatomic` and `libclang_rt.atomic`:
> 
> https://github.com/llvm/llvm-project/blob/b2dd8405d990e525e8bc823e5130eb096bd0cdd0/compiler-rt/cmake/config-ix.cmake#L21-L34

https://github.com/llvm/llvm-project/pull/106603 implements support for using compiler-rt atomic library.

https://github.com/llvm/llvm-project/pull/105732