LetNode: implement generate_function_definitions() method, fix T766

Cython/Compiler/UtilNodes.py

@@ -310,6 +310,11 @@ class LetNode(Nodes.StatNode, LetNodeMixin):
         self.body.generate_execution_code(code)
         self.teardown_temp_expr(code)
 
+    def generate_function_definitions(self, env, code):
+        self.temp_expression.generate_function_definitions(env, code)
+        self.body.generate_function_definitions(env, code)
+
+
 class TempResultFromStatNode(ExprNodes.ExprNode):
     # An ExprNode wrapper around a StatNode that executes the StatNode
     # body.  Requires a ResultRefNode that it sets up to refer to its

tests/run/letnode_T766.pyx

+# mode: run
+# ticket: 766
+# tags: letnode
+
+def test_letnode_range(int n):
+    """
+    >>> [i() for i in test_letnode_range(5)]
+    [0, 1, 2, 3, 4]
+    """
+    ret = []
+    for i in range(n):
+        def bar(x=i):
+            return x
+        ret.append(bar)
+    return ret
+
+def test_letnode_enumerate(a):
+    """
+    >>> [i() for i in test_letnode_enumerate("abc")]
+    [0, 1, 2]
+    """
+    cdef int n
+    ret = []
+    for n, i in enumerate(a):
+        def bar(x=n):
+            return x
+        ret.append(bar)
+    return ret