Add a new API, PyThreadState_DeleteCurrent() that combines
PyThreadState_Delete() and PyEval_ReleaseLock().  It is only defined
if WITH_THREAD is defined.
diff --git a/Include/pystate.h b/Include/pystate.h
index be56497..27ffe32 100644
--- a/Include/pystate.h
+++ b/Include/pystate.h
@@ -66,6 +66,9 @@
 DL_IMPORT(PyThreadState *) PyThreadState_New(PyInterpreterState *);
 DL_IMPORT(void) PyThreadState_Clear(PyThreadState *);
 DL_IMPORT(void) PyThreadState_Delete(PyThreadState *);
+#ifdef WITH_THREAD
+DL_IMPORT(void) PyThreadState_DeleteCurrent(void);
+#endif
 
 DL_IMPORT(PyThreadState *) PyThreadState_Get(void);
 DL_IMPORT(PyThreadState *) PyThreadState_Swap(PyThreadState *);