std: Minor cleanup to libtest

* Don't spawn two threads for all tests, just one now that `catch_unwind` is
  stable.
* Remove usage of the unstable `box` keyword
* Remove usage of the unstable `FnBox` trait

1 files changed, 1 insertions, 1 deletions

diff --git a/src/tools/compiletest/src/main.rs b/src/tools/compiletest/src/main.rs
index ff91ab7c70b..b81258bd6d7 100644
--- a/src/tools/compiletest/src/main.rs
+++ b/src/tools/compiletest/src/main.rs
@@ -464,7 +464,7 @@ pub fn make_test_name(config: &Config, testpaths: &TestPaths) -> test::TestName
 pub fn make_test_closure(config: &Config, testpaths: &TestPaths) -> test::TestFn {
     let config = config.clone();
     let testpaths = testpaths.clone();
-    test::DynTestFn(Box::new(move || {
+    test::DynTestFn(Box::new(move |()| {
         runtest::run(config, &testpaths)
     }))
 }