optimize: make all call single arg

to allow more aggressive optimization

src/builtins/mod.rs

@@ -17,8 +17,9 @@ pub fn env<'jit, 'vm>(vm: &'vm VM<'jit>) -> VmEnv<'jit, 'vm> {
             first.ok()
         }),
         PrimOp::new("sub", 2, |_, args| {
-            let [mut first, second]: [Value; 2] = args.try_into().unwrap();
-            first.add(second.neg());
+            let [mut first, mut second]: [Value; 2] = args.try_into().unwrap();
+            second.neg();
+            first.add(second);
             first.ok()
         }),
         PrimOp::new("mul", 2, |_, args| {