Remove max_arena_objects configuration

This isn't something we can't really control so out it goes, I guess.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

src/main.rs

@@ -17,9 +17,6 @@ struct Opt {
 
     #[structopt(long)]
     max_stack_size: Option<usize>,
-
-    #[structopt(long)]
-    max_arena_objects: Option<usize>,
 }
 
 type Result<T = (), E = Box<dyn std::error::Error>> = std::result::Result<T, E>;
@@ -43,7 +40,6 @@ fn main() -> Result {
 
     let mut machine = MachineBuilder::default()
         .max_stack_size(opt.max_stack_size)
-        .max_arena_objects(opt.max_arena_objects)
         .finish();
 
     if let Err(e) = machine.eval(stmts) {

src/vm/machine.rs

@@ -3,7 +3,6 @@ use crate::object::*;
 use crate::scope::*;
 use crate::syn::{ast::SpStmt, span::Span};
 use crate::vm::{error::*, inst::*};
-use std::cell::RefCell;
 use std::collections::BTreeMap;
 use std::rc::Rc;
 
@@ -318,7 +317,6 @@ pub struct MachineBuilder {
     pub(super) globals: BTreeMap<Word, Value>,
     pub(super) scope_stack: ScopeStack,
     pub(super) max_stack_size: Option<usize>,
-    pub(super) max_arena_objects: Option<usize>,
 }
 
 impl MachineBuilder {
@@ -327,11 +325,6 @@ impl MachineBuilder {
         self
     }
 
-    pub fn max_arena_objects(mut self, max_arena_objects: Option<usize>) -> Self {
-        self.max_arena_objects = max_arena_objects;
-        self
-    }
-
     pub(super) fn register_builtin_fun(
         &mut self,
         name: &str,