[compiler-rt] [rtsan] Add test to ensure coroutines get caught (PR #111049)

[Chris Apple via llvm-commits]

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@@ -0,0 +1,31 @@
+// RUN: %clangxx -std=c++20 -fsanitize=realtime %s -o %t
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cjappl wrote:

When running through this test on one of my older ubuntu machines, I get this error:

```
/test_radsan/llvm-project/compiler-rt/test/rtsan/coroutine.cpp:7:10: fatal error: 'coroutine' file not found
    7 | #include <coroutine>                                                                                                                                        |          ^~~~~~~~~~~
```

That led me to believe that I needed to do something special here. 

https://github.com/llvm/llvm-project/pull/111049