修正了一些错误

lib/core/Handles/HandlesExprOps.py

@@ -336,6 +336,19 @@ class ExprOpsHandle(BaseHandle):
                     }
                     result: bool = cmp_map.get(ComparatorSymbol, False)
                     return ir.Constant(ir.IntType(1), 1 if result else 0)
+            # is / is not: 值类型（IntType）与 None（空指针常量）比较
+            # 值类型（如 i8/i32）永远不可能为 None，因此：
+            #   - 值类型 is None → 恒为 false (i1 0)
+            #   - 值类型 is not None → 恒为 true (i1 1)
+            # 此检查必须在类型对齐之前，否则类型对齐会对 i8* null 执行 load（空指针解引用）导致崩溃
+            if ComparatorSymbol in ('is', 'is not'):
+                LeftIsNullPtr: bool = isinstance(LeftVal, ir.Constant) and LeftVal.constant is None and isinstance(LeftVal.type, ir.PointerType)
+                RightIsNullPtr: bool = isinstance(RightVal, ir.Constant) and RightVal.constant is None and isinstance(RightVal.type, ir.PointerType)
+                LeftIsValueType: bool = isinstance(LeftVal.type, ir.IntType)
+                RightIsValueType: bool = isinstance(RightVal.type, ir.IntType)
+                if (LeftIsValueType and RightIsNullPtr) or (RightIsValueType and LeftIsNullPtr):
+                    IsNotResult: int = 1 if ComparatorSymbol == 'is not' else 0
+                    return ir.Constant(ir.IntType(1), IsNotResult)
             if isinstance(LeftVal.type, ir.IntType) and isinstance(RightVal.type, ir.IntType):
                 if LeftVal.type.width < RightVal.type.width:
                     # 如果宽类型常量值超出窄类型有符号范围，则必须用zext