add compile-fail test sync-cond-shouldnt-escape.rs

src/test/compile-fail/sync-cond-shouldnt-escape.rs

@@ -0,0 +1,9 @@
+// error-pattern: reference is not valid outside of its lifetime
+fn main() {
+    let m = ~sync::new_mutex();
+    let mut cond = none;
+    do m.lock_cond |c| {
+        cond = some(c);
+    }   
+    option::unwrap(cond).signal();
+}