Fix compiler errors and warnings

Author: markshannon

Include/internal/pycore_frame.h

@@ -158,7 +158,6 @@ static inline void _PyFrame_Copy(_PyInterpreterFrame *src, _PyInterpreterFrame *
     dest->stackpointer = dest->localsplus + stacktop;
     for (int i = 0; i < stacktop; i++) {
         dest->localsplus[i] = PyStackRef_MakeHeapSafe(src->localsplus[i]);
-        PyStackRef_CheckValid(dest->localsplus[i]);
     }
 
 #ifdef Py_GIL_DISABLED

Python/ceval.c

@@ -1898,9 +1898,9 @@ _PyEval_Vector(PyThreadState *tstate, PyFunctionObject *func,
     if (kwnames) {
         total_args += PyTuple_GET_SIZE(kwnames);
     }
+    _PyStackRef stack_array[8];
     _PyStackRef *arguments;
     if (total_args <= 8) {
-        _PyStackRef stack_array[8];
         arguments = stack_array;
     }
     else {

Python/optimizer_bytecodes.c

@@ -193,8 +193,7 @@ dummy_func(void) {
         {
             assert(PyLong_CheckExact(sym_get_const(left)));
             assert(PyLong_CheckExact(sym_get_const(right)));
-            PyObject *temp = _PyLong_Add((PyLongObject *)sym_get_const(left),
-                                         (PyLongObject *)sym_get_const(right));
+            PyObject *temp = PyNumber_Add(sym_get_const(left), sym_get_const(right));
             if (temp == NULL) {
                 goto error;
             }