Allow inexact arguments for CALL_ALLOC_AND_ENTER_INIT.

Author: markshannon

Python/bytecodes.c

@@ -3691,15 +3691,14 @@ dummy_func(
             PyHeapTypeObject *cls = (PyHeapTypeObject *)callable_o;
             PyFunctionObject *init_func = (PyFunctionObject *)cls->_spec_cache.init;
             PyCodeObject *code = (PyCodeObject *)init_func->func_code;
-            DEOPT_IF(code->co_argcount != oparg+1);
             DEOPT_IF(!_PyThreadState_HasStackSpace(tstate, code->co_framesize + _Py_InitCleanup.co_framesize));
             STAT_INC(CALL, hit);
             self = PyStackRef_FromPyObjectSteal(_PyType_NewManagedObject(tp));
             if (PyStackRef_IsNull(self)) {
                 ERROR_NO_POP();
             }
-            init = PyStackRef_FromPyObjectNew(init_func);
             PyStackRef_CLOSE(callable);
+            init = PyStackRef_FromPyObjectNew(init_func);
         }
 
         op(_CREATE_INIT_FRAME, (self, init, args[oparg] -- init_frame: _PyInterpreterFrame *)) {
@@ -3709,12 +3708,9 @@ dummy_func(
             /* Push self onto stack of shim */
             shim->localsplus[0] = PyStackRef_DUP(self);
             PyFunctionObject *init_func = (PyFunctionObject *)PyStackRef_AsPyObjectSteal(init);
-            init_frame = _PyFrame_PushUnchecked(tstate, init_func, oparg+1, shim);
-            /* Copy self followed by args to __init__ frame */
-            init_frame->localsplus[0] = self;
-            for (int i = 0; i < oparg; i++) {
-                init_frame->localsplus[i+1] = args[i];
-            }
+            args[-1] = self;
+            init_frame = _PyEvalFramePushAndInit(
+                tstate, init_func, NULL, args-1, oparg+1, NULL, shim);
             frame->return_offset = 1 + INLINE_CACHE_ENTRIES_CALL;
             SYNC_SP();
             /* Account for pushing the extra frame.

Python/executor_cases.c.h

@@ -1814,10 +1814,6 @@ specialize_class_call(PyObject *callable, _Py_CODEUNIT *instr, int nargs)
             return -1;
         }
         if (init != NULL) {
-            if (((PyCodeObject *)init->func_code)->co_argcount != nargs+1) {
-                SPECIALIZATION_FAIL(CALL, SPEC_FAIL_WRONG_NUMBER_ARGUMENTS);
-                return -1;
-            }
             _PyCallCache *cache = (_PyCallCache *)(instr + 1);
             write_u32(cache->func_version, tp->tp_version_tag);
             _Py_SET_OPCODE(*instr, CALL_ALLOC_AND_ENTER_INIT);