Rearranged and added comments to object.h, to clarify many things

that have taken me "too long" to reverse-engineer over the years.
Vastly reduced the nesting level and redundancy of #ifdef-ery.
Took a light stab at repairing comments that are no longer true.

sys_gettotalrefcount():  Changed to enable under Py_REF_DEBUG.
It was enabled under Py_TRACE_REFS, which was much heavier than
necessary.  sys.gettotalrefcount() is now available in a
Py_REF_DEBUG-only build.

Objects/object.c

@@ -1858,9 +1858,7 @@ _Py_NewReference(PyObject *op)
 	op->_ob_prev = &refchain;
 	refchain._ob_next->_ob_prev = op;
 	refchain._ob_next = op;
-#ifdef COUNT_ALLOCS
-	inc_count(op->ob_type);
-#endif
+	_PyMAYBE_BUMP_COUNT(op);
 }
 
 void
@@ -1885,9 +1883,7 @@ _Py_ForgetReference(register PyObject *op)
 	op->_ob_next->_ob_prev = op->_ob_prev;
 	op->_ob_prev->_ob_next = op->_ob_next;
 	op->_ob_next = op->_ob_prev = NULL;
-#ifdef COUNT_ALLOCS
-	op->ob_type->tp_frees++;
-#endif
+	_PyMAYBE_BUMP_FREECOUNT(op);
 }
 
 void

Python/sysmodule.c

@@ -469,11 +469,10 @@ sys_getrefcount(PyObject *self, PyObject *arg)
 	return PyInt_FromLong(arg->ob_refcnt);
 }
 
-#ifdef Py_TRACE_REFS
+#ifdef Py_REF_DEBUG
 static PyObject *
 sys_gettotalrefcount(PyObject *self)
 {
-	extern long _Py_RefTotal;
 	return PyInt_FromLong(_Py_RefTotal);
 }
 
@@ -564,6 +563,8 @@ static PyMethodDef sys_methods[] = {
 #endif
 #ifdef Py_TRACE_REFS
 	{"getobjects",	_Py_GetObjects, METH_VARARGS},
+#endif
+#ifdef Py_REF_DEBUG
 	{"gettotalrefcount", (PyCFunction)sys_gettotalrefcount, METH_NOARGS},
 #endif
 	{"getrefcount",	(PyCFunction)sys_getrefcount, METH_O, getrefcount_doc},