attempt rewriting last condition in link-dedup

Author: Oneirical

tests/run-make/link-dedup/rmake.rs

@@ -29,6 +29,11 @@ fn main() {
     assert!(output.contains("-ltesta"));
     let output = String::from_utf8(rustc().input("empty.rs").command_output().stderr).unwrap();
     assert!(!output.contains("-ltestb"));
-    let output = String::from_utf8(rustc().input("empty.rs").command_output().stderr).unwrap();
-    assert_eq!(output.matches("-ltesta").count(), 1);
+    let output = rustc().input("empty.rs").command_output().stderr;
+    let pattern = b"\"-ltesta\" \"-ltesta\" \"-ltesta\"";
+    for window in output.windows(pattern.len()) {
+        if window == pattern {
+            panic!("ltesta was repeated too many times");
+        }
+    }
 }