refactor: 统一调用调度并安全化 IC 缓存

crates/oxide_vm/src/dispatch/call.rs

@@ -1,5 +1,5 @@
-use crate::native::NativeFn;
-use crate::vm::Vm;
+use crate::native::{NativeFn, NativeResult};
+use crate::vm::{native_fn_ptr_to_fn, FrameContinuation, Vm};
 use oxide_types::object::JsObject;
 use oxide_types::value::JsValue;
 
@@ -25,16 +25,18 @@ impl Vm {
         let (args_buf, len) = Self::build_native_args(first_arg_reg, arg_count, this_reg);
         let args_slice = &args_buf[..len];
 
-        let func: NativeFn = unsafe { std::mem::transmute(obj.native_fn().unwrap()) };
+        // SAFETY: native_fn was set via set_native_fn with a valid NativeFn pointer;
+        // native_fn_ptr_to_fn is the single coercion point for NativeFnPtr → NativeFn.
+        let func: NativeFn = unsafe { native_fn_ptr_to_fn(obj.native_fn().unwrap()) };
         self.regs[254] = callee;
         self.native_call_depth += 1;
         match func(self, args_slice) {
-            Ok(val) => {
+            NativeResult::Ok(val) => {
                 self.native_call_depth -= 1;
                 self.regs[0] = val;
                 Ok(())
             }
-            Err(err_val) => {
+            NativeResult::Err(err_val) => {
                 self.native_call_depth -= 1;
                 let (error, kind) = if err_val.is_object() {
                     (err_val, self.thrown_error_kind(err_val))
@@ -53,6 +55,18 @@ impl Vm {
                 self.pending_error_kind = Some(kind);
                 self.unwind()
             }
+            NativeResult::TailCall { callee, this, args } => {
+                self.native_call_depth -= 1;
+                if callee.is_object() {
+                    let obj = unsafe { &*callee.as_js_object_ptr() };
+                    if obj.native_fn().is_some() {
+                        let result = self.call_function_sync(callee, this, &args)?;
+                        self.regs[0] = result;
+                        return Ok(());
+                    }
+                }
+                self.push_bytecode_frame(callee, this, &args, None, None, JsValue::undefined(), FrameContinuation::None)
+            }
         }
     }
 }