[compiler-rt] [llvm] [ctxprof] root autodetection mechanism (PR #133147)

[Paul Kirth via llvm-commits]

ilovepi wrote:

We're seeing some test failures after this patch, would you mind taking a look. This is on linux-x86_64. There isn't too much special in our CMake, but since we use a very recent clang to build it, maybe its easiest to repro w/ a 2 stage build.

** Failing Test:** 
- CtxProfile-x86_64-linux :: TestCases/autodetect-roots.cpp
- CtxProfile-x86_64-linux :: TestCases/generate-context.cpp

**Failing Bot:**
https://ci.chromium.org/ui/p/fuchsia/builders/toolchain.ci/clang-linux-x64/b8718149220847740529/overview.


https://github.com/llvm/llvm-project/pull/133147