refactor: 进一步拆分函数执行逻辑以简化主流程

crates/oxide_vm/src/dispatch/misc.rs

@@ -1 +1,40 @@
-// dispatch helper functions extracted from vm.rs
+use crate::vm::Vm;
+
+impl Vm {
+    #[inline(always)]
+    pub(crate) fn dispatch_load_const(&mut self, rd: usize, instr: u32) -> Result<(), String> {
+        let idx = (instr >> 16) as usize;
+        if idx < self.constants.len() {
+            self.regs[rd] = self.constants[idx];
+            Ok(())
+        } else {
+            Err(format!("constant index {idx} out of bounds"))
+        }
+    }
+
+    #[inline(always)]
+    pub(crate) fn dispatch_typeof(&mut self, rd: usize, a: usize) {
+        let val = self.regs[a];
+        let result = if val.is_undefined() {
+            "undefined"
+        } else if val.is_null() {
+            "object"
+        } else if val.is_bool() {
+            "boolean"
+        } else if val.is_int() || val.is_double() {
+            "number"
+        } else if val.is_string() {
+            "string"
+        } else if val.is_object() {
+            let obj = unsafe { &*val.as_js_object_ptr() };
+            if obj.is_function() {
+                "function"
+            } else {
+                "object"
+            }
+        } else {
+            "undefined"
+        };
+        self.regs[rd] = self.intern(result);
+    }
+}