Uncomment timedelta macros in datetime.pxd, because why not have them?

CHANGES.rst

@@ -47,6 +47,8 @@ Bugs fixed
   was not declared as ``extern "C"``.
   (Github issue #3414)
 
+* Three missing timedelta access macros were added in ``cpython.datetime``.
+
 
 0.29.17 (2020-04-26)
 ====================

Cython/Includes/cpython/datetime.pxd

@@ -90,9 +90,9 @@ cdef extern from "datetime.h":
     int PyDateTime_TIME_GET_MICROSECOND(object o)
 
     # Getters for timedelta (C macros).
-    #int PyDateTime_DELTA_GET_DAYS(object o)
-    #int PyDateTime_DELTA_GET_SECONDS(object o)
-    #int PyDateTime_DELTA_GET_MICROSECONDS(object o)
+    int PyDateTime_DELTA_GET_DAYS(object o)
+    int PyDateTime_DELTA_GET_SECONDS(object o)
+    int PyDateTime_DELTA_GET_MICROSECONDS(object o)
 
     # PyDateTime CAPI object.
     PyDateTime_CAPI *PyDateTimeAPI