修复了大量存在的问题，增加了假鸭子类型等等机制

Test/LoopTest/temp/86e203c56ae4de20.pyi

@@ -0,0 +1,27 @@
+"""
+Auto-generated Python stub file from main.py
+Module: main
+"""
+
+import c
+
+
+import t
+import stdio
+import testcheck
+
+def test_for_loop() -> t.CInt: pass
+
+def test_while_loop() -> t.CInt: pass
+
+def test_nested_loop() -> t.CInt: pass
+
+def test_break() -> t.CInt: pass
+
+def test_continue() -> t.CInt: pass
+
+def test_range_step() -> t.CInt: pass
+
+def test_loop_u64() -> t.CInt: pass
+
+def main() -> t.CInt: pass