[llvm] [llvm][DebugInfo] Drop \01 mangling prefix when inserting linkage name into accelerator table (PR #138852)

[Michael Buch via llvm-commits]

Michael137 wrote:

CI error is unrelated. Seems like a flang build failure:
```
fatal error: file '/var/lib/buildkite-agent/builds/linux-56-59b8f5d88-g6cdk-1/llvm-project/github-pull-requests/llvm/include/llvm/ADT/bit.h' has been modified since the precompiled header '/var/lib/buildkite-agent/builds/linux-56-59b8f5d88-g6cdk-1/llvm-project/github-pull-requests/build/tools/flang/lib/Evaluate/CMakeFiles/FortranEvaluate.dir/cmake_pch.hxx.pch' was built: size changed (was 12409, now 12384)
note: please rebuild precompiled header '/var/lib/buildkite-agent/builds/linux-56-59b8f5d88-g6cdk-1/llvm-project/github-pull-requests/build/tools/flang/lib/Evaluate/CMakeFiles/FortranEvaluate.dir/cmake_pch.hxx.pch'
1 error generated.
```

https://github.com/llvm/llvm-project/pull/138852