Merge 3.2 (linked to issue #1294232)

diff --cc Python/bltinmodule.c
index fd242b7408e6ca4b29b87e0a74b331ccee8eba08,d05232c34af592a56d21cdf93d5746423b6db948..0c14d7e3261656aaa43897fa73d227a7f59d1e23
--- 1/Python/bltinmodule.c
--- 2/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@@ -40,9 -37,8 +40,9 @@@ builtin___build_class__(PyObject *self
  {
      PyObject *func, *name, *bases, *mkw, *meta, *winner, *prep, *ns, *cell;
      PyObject *cls = NULL;
-     Py_ssize_t nargs, nbases;
+     Py_ssize_t nargs;
      int isclass;
 +    _Py_IDENTIFIER(__prepare__);
  
      assert(args != NULL);
      if (!PyTuple_Check(args)) {