merge the fuzzers into one

fuzz/fuzz_targets/deserialize_br.rs

@@ -17,33 +17,16 @@ fuzz_target!(|data: &[u8]| {
     let b1 = node_to_bytes_backrefs(&allocator, program).unwrap();
 
     let mut allocator = Allocator::new();
+    let cp = allocator.checkpoint();
     let program = node_from_bytes_backrefs(&mut allocator, &b1).unwrap();
+    let new_pair_count = allocator.pair_count();
+    allocator.restore_checkpoint(&cp);
     let program_old = node_from_bytes_backrefs_old(&mut allocator, &b1).unwrap();
+    // check we aren't making more nodes in the new version
+    assert!(new_pair_count <= allocator.pair_count());
+    // check that the two versions of the deserializer produce the same/correct result
     let b2 = node_to_bytes_backrefs(&allocator, program).unwrap();
     assert_eq!(b1, b2);
     let b3 = node_to_bytes_backrefs(&allocator, program_old).unwrap();
     assert_eq!(b1, b3);
 });
-
-// #[cfg(feature = "counters")]
-fuzz_target!(|data: &[u8]| {
-    let mut allocator = Allocator::new();
-    let cp = allocator.checkpoint();
-    let program = match node_from_bytes_backrefs(&mut allocator, data) {
-        Err(_) => {
-            return;
-        }
-        Ok(r) => r,
-    };
-
-    let b1 = node_to_bytes_backrefs(&allocator, program).unwrap();
-
-    // reset allocators
-    allocator.restore_checkpoint(&cp);
-
-    let _program = node_from_bytes_backrefs(&mut allocator, &b1).unwrap();
-    let new_pair_count = allocator.pair_count();
-    allocator.restore_checkpoint(&cp);
-    let _program_old = node_from_bytes_backrefs_old(&mut allocator, &b1).unwrap();
-    assert!(new_pair_count <= allocator.pair_count());
-});