Address review comments

Author: Fidget-Spinner

Objects/funcobject.c

@@ -381,7 +381,9 @@ _PyFunction_ClearCodeByVersion(uint32_t version)
 PyFunctionObject *
 _PyFunction_LookupByVersion(uint32_t version, PyObject **p_code)
 {
-#if _Py_TIER2
+#ifndef _Py_TIER2
+    return NULL;
+#else
     // This function does not need locking/atomics as it can only be
     // called from the optimizer, which is currently disabled
     // when there are multiple threads.
@@ -402,8 +404,6 @@ _PyFunction_LookupByVersion(uint32_t version, PyObject **p_code)
         return slot->func;
     }
     return NULL;
-#else
-    return NULL;
 #endif
 }
 

Objects/typeobject.c

@@ -1150,8 +1150,8 @@ set_version_unlocked(PyTypeObject *tp, unsigned int version)
 {
     assert(version == 0 || (tp->tp_versions_used != _Py_ATTR_CACHE_UNUSED));
 #if _Py_TIER2
+    ASSERT_TYPE_LOCK_HELD();
     PyInterpreterState *interp = _PyInterpreterState_GET();
-    BEGIN_TYPE_LOCK();
     // lookup the old version and set to null
     if (tp->tp_version_tag != 0) {
         PyTypeObject **slot =

Python/sysmodule.c

@@ -4125,7 +4125,7 @@ _jit_is_enabled_impl(PyObject *module)
 /*[clinic end generated code: output=55865f8de993fe42 input=0524151e857f4f3a]*/
 {
     (void)module;
-    return _PyInterpreterState_GET()->jit;
+    return FT_ATOMIC_LOAD_UINT8_RELAXED(_PyInterpreterState_GET()->jit);
 }
 
 /*[clinic input]