fix compiler crash on none checks after in-place operations

Cython/Compiler/FlowControl.py

@@ -711,7 +711,9 @@ class CreateControlFlowGraph(CythonTransform):
         self.in_inplace_assignment = True
         self.visitchildren(node)
         self.in_inplace_assignment = False
-        self.mark_assignment(node.lhs, node.create_binop_node())
+        expr_node = node.create_binop_node()
+        expr_node.type = expr_node.infer_type(self.env)
+        self.mark_assignment(node.lhs, expr_node)
         return node
 
     def visit_DelStatNode(self, node):

tests/run/cf_none.pyx

@@ -113,3 +113,10 @@ def self_dependency_none(int x):
     if x:
         a,b = b,a
     return b.get(2)
+
+#@cython.test_fail_if_path_exists('//NoneCheckNode')
+def in_place_op():
+    vals = [0]
+    vals += [1]
+    for x in vals:
+        pass