Fix additional data races

Author: colesbury

Objects/exceptions.c

@@ -4231,7 +4231,8 @@ _PyExc_InitTypes(PyInterpreterState *interp)
             return -1;
         }
         if (exc->tp_new == BaseException_new
-            && exc->tp_init == (initproc)BaseException_init)
+            && exc->tp_init == (initproc)BaseException_init
+            && _Py_IsMainInterpreter(interp))
         {
             exc->tp_vectorcall = BaseException_vectorcall;
         }

Objects/typeobject.c

@@ -234,10 +234,9 @@ managed_static_type_state_init(PyInterpreterState *interp, PyTypeObject *self,
         ? index
         : index + _Py_MAX_MANAGED_STATIC_BUILTIN_TYPES;
 
-    assert((initial == 1) ==
-            (_PyRuntime.types.managed_static.types[full_index].interp_count == 0));
-    (void)_Py_atomic_add_int64(
+    int64_t prev_interp_count = _Py_atomic_add_int64(
             &_PyRuntime.types.managed_static.types[full_index].interp_count, 1);
+    assert((initial == 1) == (prev_interp_count == 0));
 
     if (initial) {
         assert(_PyRuntime.types.managed_static.types[full_index].type == NULL);
@@ -8526,7 +8525,12 @@ type_ready_set_new(PyTypeObject *type, int initial)
         }
         else {
             // tp_new is NULL: inherit tp_new from base
-            type->tp_new = base->tp_new;
+            if (initial) {
+                type->tp_new = base->tp_new;
+            }
+            else {
+                assert(type->tp_new == base->tp_new);
+            }
         }
     }
     else {