pass jobserver on target info acquiring

Author: belovdv

src/cargo/core/compiler/build_context/target_info.rs

@@ -185,6 +185,10 @@ impl TargetInfo {
                 .args(&rustflags)
                 .env_remove("RUSTC_LOG");
 
+            if let Some(client) = config.jobserver_from_env() {
+                process.inherit_jobserver(client);
+            }
+
             if let CompileKind::Target(target) = kind {
                 process.arg("--target").arg(target.rustc_target());
             }