fix `llvm_out` to use the correct LLVM root When `download-ci-llvm` is enabled, `llvm_out` ends up with the error below due to an incorrect path on cross-compilations. This change fixes that. ```sh failed to execute command: "/rust/build/x86_64-unknown-linux-gnu/llvm/build/bin/llvm-config" "--version" ERROR: No such file or directory (os error 2) ```
This directory contains some source code for the Rust project, including:
- The bootstrapping build system
- Various submodules for tools, like cargo, tidy, etc.
For more information on how various parts of the compiler work, see the rustc dev guide.