Resolve all warnings in `run-coverage` tests

When one of these tests fails, any compiler warnings will be printed to the
console, which makes it harder to track down the actual reason for failure.

(The outstanding warnings were found by temporarily adding `-Dwarnings` to the
compiler arguments for `RunCoverage` in `src/tools/compiletest/src/runtest.rs`.)

1 files changed, 0 insertions, 6 deletions

diff --git a/tests/run-coverage/async2.rs b/tests/run-coverage/async2.rs
index 959d48ce9db..21f4e65de30 100644
--- a/tests/run-coverage/async2.rs
+++ b/tests/run-coverage/async2.rs
@@ -1,11 +1,5 @@
 // compile-flags: --edition=2018
 
-use core::{
-    future::Future,
-    marker::Send,
-    pin::Pin,
-};
-
 fn non_async_func() {
     println!("non_async_func was covered");
     let b = true;