perf: run 签名改 &Arc<CompiledModule>，顶层模块跨 run 共享——collect_flat_modules 顶层改 Arc::clone 消除逐 run 常量池深拷贝，全调用点 Arc 包装迁移

crates/oxide_vm/tests/object_tests.rs

@@ -1,3 +1,5 @@
+use std::sync::Arc;
+
 use oxide_compiler::compiler::Compiler;
 use oxide_parser::Allocator;
 use oxide_vm::vm::Vm;
@@ -13,7 +15,7 @@ fn eval(source: &str) -> String {
         Err(e) => return format!("compile error: {e}"),
     };
     let mut vm = Vm::new();
-    match vm.run(&module) {
+    match vm.run(&Arc::new(module)) {
         Ok(result) => format!("{result}"),
         Err(e) => format!("vm error: {e}"),
     }
@@ -26,7 +28,7 @@ fn object_create_and_read() {
     let program = oxide_parser::parse(&allocator, source).expect("parse failed");
     let module = Compiler::new().compile(&program).expect("compile failed");
     let mut vm = Vm::new();
-    let obj = vm.run(&module).expect("vm run failed");
+    let obj = vm.run(&Arc::new(module)).expect("vm run failed");
     assert!(obj.is_object());
     let obj_ref = unsafe { &*obj.as_js_object_ptr() };
     assert_eq!(obj_ref.prop_count(), 1, "object should have 1 property");
@@ -273,7 +275,7 @@ fn eval_string(source: &str) -> String {
     let mut vm = Vm::new();
     let program = oxide_parser::parse(&allocator, source).expect("parse failed");
     let module = Compiler::new().compile(&program).expect("compile failed");
-    let result = vm.run(&module).expect("vm run failed");
+    let result = vm.run(&Arc::new(module)).expect("vm run failed");
     vm.lookup_str(result).unwrap_or_default()
 }