Fix: overwrite target node after analysis.

Cython/Compiler/Nodes.py

@@ -4951,7 +4951,7 @@ class PyClassDefNode(ClassDefNode):
         self.class_result = self.class_result.analyse_expressions(env)
         cenv = self.scope
         self.body = self.body.analyse_expressions(cenv)
-        self.target.analyse_target_expression(env, self.classobj)
+        self.target = self.target.analyse_target_expression(env, self.classobj)
         self.class_cell = self.class_cell.analyse_expressions(cenv)
         return self
 

Cython/Compiler/ParseTreeTransforms.py

@@ -2446,8 +2446,8 @@ class ExpandInplaceOperators(EnvTransform):
                                      operand2 = rhs,
                                      inplace=True)
         # Manually analyse types for new node.
-        lhs.analyse_target_types(env)
-        dup.analyse_types(env)
+        lhs = lhs.analyse_target_types(env)
+        dup.analyse_types(env)  # FIXME: no need to reanalyse the copy, right?
         binop.analyse_operation(env)
         node = Nodes.SingleAssignmentNode(
             node.pos,