Fix 3.x generator bug...

found by Daniel Brandburn. See
af61622960

test/simple_source/expression/11_multi_genexpr.py

@@ -0,0 +1,24 @@
+# Had bug in Python 3.x
+
+# Should see (Python 2.x and 3.x:
+# get_iter ::= expr GET_ITER
+# expr ::= get_iter
+# _for ::= GET_ITER FOR_ITER
+# designator ::= STORE_FAST
+# expr ::= LOAD_FAST
+# yield ::= expr YIELD_VALUE
+# expr ::= yield
+# gen_comp_body ::= expr YIELD_VALUE POP_TOP
+# comp_body ::= gen_comp_body
+# comp_iter ::= comp_body
+# comp_for ::= expr _for designator comp_iter JUMP_BACK
+# comp_iter ::= comp_for
+# genexpr_func ::= LOAD_FAST FOR_ITER designator comp_iter JUMP_BACK
+
+def multi_genexpr(blog_posts):
+
+    return (
+        entry
+        for blog_post in blog_posts
+        for entry in blog_post.entry_set
+    )