pythongh-128262: Allow specialization of calls to classes with __slots__ (pythonGH-128263)

Author: Fidget-Spinner

Include/internal/pycore_uop_metadata.h

@@ -3765,13 +3765,15 @@ dummy_func(
             DEOPT_IF(!PyType_Check(callable_o));
             PyTypeObject *tp = (PyTypeObject *)callable_o;
             DEOPT_IF(FT_ATOMIC_LOAD_UINT32_RELAXED(tp->tp_version_tag) != type_version);
-            assert(tp->tp_flags & Py_TPFLAGS_INLINE_VALUES);
+            assert(tp->tp_new == PyBaseObject_Type.tp_new);
+            assert(tp->tp_flags & Py_TPFLAGS_HEAPTYPE);
+            assert(tp->tp_alloc == PyType_GenericAlloc);
             PyHeapTypeObject *cls = (PyHeapTypeObject *)callable_o;
             PyFunctionObject *init_func = (PyFunctionObject *)FT_ATOMIC_LOAD_PTR_ACQUIRE(cls->_spec_cache.init);
             PyCodeObject *code = (PyCodeObject *)init_func->func_code;
             DEOPT_IF(!_PyThreadState_HasStackSpace(tstate, code->co_framesize + _Py_InitCleanup.co_framesize));
             STAT_INC(CALL, hit);
-            PyObject *self_o = _PyType_NewManagedObject(tp);
+            PyObject *self_o = PyType_GenericAlloc(tp, 0);
             if (self_o == NULL) {
                 ERROR_NO_POP();
             }

Python/bytecodes.c

@@ -2002,10 +2002,6 @@ get_init_for_simple_managed_python_class(PyTypeObject *tp, unsigned int *tp_vers
         return NULL;
     }
     unsigned long tp_flags = PyType_GetFlags(tp);
-    if ((tp_flags & Py_TPFLAGS_INLINE_VALUES) == 0) {
-        SPECIALIZATION_FAIL(CALL, SPEC_FAIL_CALL_INIT_NOT_INLINE_VALUES);
-        return NULL;
-    }
     if (!(tp_flags & Py_TPFLAGS_HEAPTYPE)) {
         /* Is this possible? */
         SPECIALIZATION_FAIL(CALL, SPEC_FAIL_EXPECTED_ERROR);