修复了大量存在的问题，增加了假鸭子类型等等机制

Test/ClosureTest2/temp/440f18f9dce85a95.pyi

@@ -0,0 +1,52 @@
+"""
+Auto-generated Python stub file from main.py
+Module: main
+"""
+
+import c
+
+
+import t
+import stdio
+import testcheck
+
+def test_nonlocal_conditional() -> t.CInt: pass
+
+def test_nonlocal_multi_var() -> t.CInt: pass
+
+
+g_counter: t.CExtern | t.CInt
+
+def inc_global() -> t.CInt: pass
+
+def add_global(n: t.CInt) -> t.CInt: pass
+
+def test_global_cross_functions() -> t.CInt: pass
+
+def test_nested_ref_capture() -> t.CInt: pass
+
+def test_lambda_capture_then_modify() -> t.CInt: pass
+
+def test_nonlocal_loop_accumulate() -> t.CInt: pass
+
+def test_deep_nested_vars() -> t.CInt: pass
+
+
+g_state: t.CExtern | t.CInt
+
+def test_global_nonlocal_same_func() -> t.CInt: pass
+
+def test_lambda_default_and_capture() -> t.CInt: pass
+
+def test_nested_accumulate() -> t.CInt: pass
+
+def test_nonlocal_while() -> t.CInt: pass
+
+
+class Point:
+    x: t.CInt
+    y: t.CInt
+
+def test_nested_modify_struct() -> t.CInt: pass
+
+def main() -> t.CInt: pass