Address code review

Author: corona10

Objects/genobject.c

@@ -721,6 +721,7 @@ gen_set_name(PyObject *self, PyObject *value, void *Py_UNUSED(ignored))
         return -1;
     }
     Py_BEGIN_CRITICAL_SECTION(self);
+    // To prevent use-after-free from other threads that reference the gi_name.
     _PyObject_XSetRefDelayed(&op->gi_name, Py_NewRef(value));
     Py_END_CRITICAL_SECTION();
     return 0;
@@ -746,6 +747,7 @@ gen_set_qualname(PyObject *self, PyObject *value, void *Py_UNUSED(ignored))
         return -1;
     }
     Py_BEGIN_CRITICAL_SECTION(self);
+    // To prevent use-after-free from other threads that reference the gi_qualname.
     _PyObject_XSetRefDelayed(&op->gi_qualname, Py_NewRef(value));
     Py_END_CRITICAL_SECTION();
     return 0;

Objects/typeobject.c

@@ -3967,6 +3967,7 @@ _PyObject_SetDict(PyObject *obj, PyObject *value)
         return -1;
     }
     Py_BEGIN_CRITICAL_SECTION(obj);
+    // To prevent use-after-free from other threads that reference the __dict__
     _PyObject_XSetRefDelayed(dictptr, Py_NewRef(value));
     Py_END_CRITICAL_SECTION();
     return 0;