General code fixups.

tests/native.rs

@@ -30,6 +30,7 @@ fn test_native_context_fn_name() -> Result<(), Box<EvalAltResult>> {
 
     let mut engine = Engine::new();
 
+    #[allow(deprecated)]
     engine
         .register_raw_fn(
             "add_double",

tests/switch.rs

@@ -160,6 +160,7 @@ mod test_switch_enum {
     use super::*;
     use rhai::Array;
     #[derive(Debug, Clone)]
+    #[allow(dead_code)]
     enum MyEnum {
         Foo,
         Bar(INT),