Fixed problems in the last commit. Filenames and line numbers weren't reported correctly.
Backquotes still don't report the correct file. The AST nodes only contain the line number but not the file name.
diff --git a/Python/ast.c b/Python/ast.c
index 5555cf7..9354b59 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -1336,10 +1336,14 @@
         return Dict(keys, values, LINENO(n), n->n_col_offset, c->c_arena);
     }
     case BACKQUOTE: { /* repr */
-        if (Py_Py3kWarningFlag &&
-            PyErr_Warn(PyExc_DeprecationWarning,
-                "backquote not supported in 3.x") < 0)
-            return NULL;
+        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 (!expression)
             return NULL;