Migrate run-make/used to migrate.rs

Author: GuillaumeGomez

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -255,7 +255,6 @@ run-make/unknown-mod-stdin/Makefile
 run-make/unstable-flag-required/Makefile
 run-make/use-suggestions-rust-2018/Makefile
 run-make/used-cdylib-macos/Makefile
-run-make/used/Makefile
 run-make/volatile-intrinsics/Makefile
 run-make/wasm-exceptions-nostd/Makefile
 run-make/wasm-override-linker/Makefile

tests/run-make/used/Makefile

@@ -0,0 +1,16 @@
+//! This test checks rustdoc `-` (stdin) handling
+
+use run_make_support::{rustc, tmp_dir};
+use std::process::Command;
+
+fn main() {
+    rustc().opt_level("3").emit("obj").input("used.rs").run();
+
+    let output = Command::new("nm").arg(tmp_dir().join("used.o")).output().unwrap();
+
+    assert!(output.status.success());
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    if !stdout.contains("FOO") {
+        panic!("`FOO` not found in stdout:\n`{stdout}`");
+    }
+}