fix(Translator): 类体 CDefine 预扫描扩展 + CDefine 类型修复（i32）

- GenerateLlvmDirect 预扫描扩展到类体 AnnAssign，注册类体 CDefine 常量
  （方法内裸名如 ISINSTANCE_CLASS_MAX 不再解析为 0）
- t.py CDefine Size/IsSigned 覆盖为 32 位有符号，修复 stub 生成 void 类型
- 新增 Test/TpvIsinstanceTest（TPV 侧 isinstance 回归测试）

lib/core/Translator/LlvmGenerator.py

@@ -74,30 +74,44 @@ class LlvmGeneratorMixin:
             # 使用 ConstEvaluator 处理 BinOp/UnaryOp/Name/Attribute/Call
             return ConstEvaluator.eval_with_symtab(node, self.SymbolTable)
 
+        def _is_cdefine_type(TypeInfo: CTypeInfo | None) -> bool:
+            """判断 CTypeInfo 是否对应 t.CDefine 注解"""
+            return bool(TypeInfo and TypeInfo.BaseType and
+                        ((isinstance(TypeInfo.BaseType, type) and issubclass(TypeInfo.BaseType, t.CDefine))
+                         or isinstance(TypeInfo.BaseType, t.CDefine) or TypeInfo.IsDefine))
+
+        def _register_cdefine_constant(NameNode: ast.Name, Annotation: ast.expr, Value: ast.expr) -> None:
+            """注册 CDefine 编译期常量（_define_constants + SymbolTable）"""
+            TypeInfo: CTypeInfo | None = self.TypeMergeHandler.GetCTypeInfo(Annotation)
+            if not _is_cdefine_type(TypeInfo):
+                return
+            val: int | str | float | None = _extract_const_value(Value)
+            if val is not None:
+                if not hasattr(Gen, '_define_constants'):
+                    Gen._define_constants: dict[str, int | str | float | bool] = {}
+                Gen._define_constants[NameNode.id] = val
+                existing = self.SymbolTable.lookup(NameNode.id)
+                if not (existing and existing.IsTypedef and existing.OriginalType):
+                    sym_info: _CTypeInfo = _CTypeInfo()
+                    sym_info.IsDefine = True
+                    sym_info.DefineValue = val
+                    self.SymbolTable.insert(NameNode.id, sym_info)
+
         for Node in ast.iter_child_nodes(Tree):
             if isinstance(Node, ast.AnnAssign) and isinstance(Node.target, ast.Name) and Node.value:
                 TypeInfo: CTypeInfo | None = self.TypeMergeHandler.GetCTypeInfo(Node.annotation)
                 # 治本修复：检查 BaseType 是否为 t.CDefine 实例/子类，或 IsDefine 标志
                 # IsDefine 由 GetCTypeInfo 对 t.CDefine 注解自动设置
-                if TypeInfo and TypeInfo.BaseType and ((isinstance(TypeInfo.BaseType, type) and issubclass(TypeInfo.BaseType, t.CDefine)) or isinstance(TypeInfo.BaseType, t.CDefine) or TypeInfo.IsDefine):
-                    val: int | str | float | None = _extract_const_value(Node.value)
-                    import sys as _sys
-                    _nm = Node.target.id
-                    # [CD] 仅输出关键常量（FOREGROUND_*, STD_OUTPUT_HANDLE, BACKGROUND_*）
-                    if isinstance(_nm, str) and (_nm.startswith('FOREGROUND_') or _nm.startswith('BACKGROUND_') or 'STD_' in _nm or 'HANDLE' in _nm):
-                        print(f"[CD] extract: '{_nm}' IsDefine={TypeInfo.IsDefine} val={val}", file=_sys.stderr, flush=True)
-                    if val is not None:
-                        if not hasattr(Gen, '_define_constants'):
-                            Gen._define_constants: dict[str, int | str | float | bool] = {}
-                        Gen._define_constants[Node.target.id] = val
-                        existing = self.SymbolTable.lookup(Node.target.id)
-                        if not (existing and existing.IsTypedef and existing.OriginalType):
-                            sym_info: _CTypeInfo = _CTypeInfo()
-                            sym_info.IsDefine = True
-                            sym_info.DefineValue = val
-                            self.SymbolTable.insert(Node.target.id, sym_info)
-                    else:
-                        print(f"[CD] extract: WARN val is None for '{_nm}'", file=_sys.stderr, flush=True)
+                if _is_cdefine_type(TypeInfo):
+                    _register_cdefine_constant(Node.target, Node.annotation, Node.value)
+            elif isinstance(Node, ast.ClassDef):
+                # 类体 CDefine 常量（2026-08-10）：供方法内裸名（如 Mixin 的
+                # ISINSTANCE_CLASS_MAX/MRO_MAX: t.CDefine = N）编译期解析为常量值。
+                # 原预扫描只用 iter_child_nodes 扫顶层，类体常量不注册 → 方法内
+                # 裸名解析为 0 → pool.alloc(8*0) 失败（TPV 编译测试 SUBS-NONE）。
+                for _citem in Node.body:
+                    if isinstance(_citem, ast.AnnAssign) and isinstance(_citem.target, ast.Name) and _citem.value:
+                        _register_cdefine_constant(_citem.target, _citem.annotation, _citem.value)
             elif isinstance(Node, ast.Assign):
                 for target in Node.targets:
                     if isinstance(target, ast.Name):