Fix pattern matching mode changes and unsafe_op_in_unsafe_fn

Author: compiler-errors

library/alloc/src/collections/btree/merge_iter.rs

@@ -74,7 +74,7 @@ impl<I: Iterator> MergeIterInner<I> {
                 b_next = self.b.next();
             }
         }
-        if let (Some(ref a1), Some(ref b1)) = (&a_next, &b_next) {
+        if let (Some(a1), Some(b1)) = (&a_next, &b_next) {
             match cmp(a1, b1) {
                 Ordering::Less => self.peeked = b_next.take().map(Peeked::B),
                 Ordering::Greater => self.peeked = a_next.take().map(Peeked::A),

library/std/src/sync/mpmc/mod.rs

@@ -616,9 +616,9 @@ impl<T> Sender<T> {
     #[unstable(feature = "mpmc_channel", issue = "126840")]
     pub fn same_channel(&self, other: &Sender<T>) -> bool {
         match (&self.flavor, &other.flavor) {
-            (SenderFlavor::Array(ref a), SenderFlavor::Array(ref b)) => a == b,
-            (SenderFlavor::List(ref a), SenderFlavor::List(ref b)) => a == b,
-            (SenderFlavor::Zero(ref a), SenderFlavor::Zero(ref b)) => a == b,
+            (SenderFlavor::Array(a), SenderFlavor::Array(b)) => a == b,
+            (SenderFlavor::List(a), SenderFlavor::List(b)) => a == b,
+            (SenderFlavor::Zero(a), SenderFlavor::Zero(b)) => a == b,
             _ => false,
         }
     }

library/test/src/lib.rs

@@ -184,12 +184,16 @@ pub fn test_main_static_abort(tests: &[&TestDescAndFn]) {
     // If we're being run in SpawnedSecondary mode, run the test here. run_test
     // will then exit the process.
     if let Ok(name) = env::var(SECONDARY_TEST_INVOKER_VAR) {
-        env::remove_var(SECONDARY_TEST_INVOKER_VAR);
+        unsafe {
+            env::remove_var(SECONDARY_TEST_INVOKER_VAR);
+        }
 
         // Convert benchmarks to tests if we're not benchmarking.
         let mut tests = tests.iter().map(make_owned_test).collect::<Vec<_>>();
         if env::var(SECONDARY_TEST_BENCH_BENCHMARKS_VAR).is_ok() {
-            env::remove_var(SECONDARY_TEST_BENCH_BENCHMARKS_VAR);
+            unsafe {
+                env::remove_var(SECONDARY_TEST_BENCH_BENCHMARKS_VAR);
+            }
         } else {
             tests = convert_benchmarks_to_tests(tests);
         };