And yet another fix for the patch. Paul Moore has send me a note that I've missed a declaration. The additional code has moved the declaration in the middle of the block.
diff --git a/Python/ast.c b/Python/ast.c
index a9bc2d4..b97da1d 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -1336,15 +1336,16 @@
         return Dict(keys, values, LINENO(n), n->n_col_offset, c->c_arena);
     }
     case BACKQUOTE: { /* repr */
+        expr_ty expression;
         if (Py_Py3kWarningFlag) {
-		if (PyErr_WarnExplicit(PyExc_DeprecationWarning,
-				       "backquote not supported in 3.x",
-				       "<unknown>", LINENO(n),
-				       NULL, NULL)) {
-			return NULL;
-		}
-	}
-        expr_ty expression = ast_for_testlist(c, CHILD(n, 1));
+            if (PyErr_WarnExplicit(PyExc_DeprecationWarning,
+                                   "backquote not supported in 3.x",
+                                   "<unknown>", LINENO(n),
+                                   NULL, NULL)) {
+            return NULL;
+            }
+        }
+        expression = ast_for_testlist(c, CHILD(n, 1));
         if (!expression)
             return NULL;