Also install the symlink

Author: nikic

src/bootstrap/src/core/build_steps/dist.rs

@@ -2027,9 +2027,12 @@ fn install_llvm_file(builder: &Builder<'_>, source: &Path, destination: &Path) {
     }
 
     if source.is_symlink() {
-        // Follow symlinks. E.g. if we're linking against libLLVM-18.so, then what gets loaded
-        // at runtime is libLLVM.so.18.1.
+        // If we have a symlink like libLLVM-18.so -> libLLVM.so.18.1, install both the target
+        // and the symlink. The target is what will get loaded at runtime. The symlink is what
+        // will be used for linking when download-ci-llvm is used.
         builder.install(&t!(fs::canonicalize(source)), destination, 0o644);
+        let full_dest = destination.join(source.file_name().unwrap());
+        builder.copy(&source, &full_dest);
     } else {
         builder.install(&source, destination, 0o644);
     }