Issue #8259: Get rid of 'outrageous left shift count' error when

left-shifting an integer by more than 2**31 on a 64-bit machine.  Also
convert shift counts to a Py_ssize_t instead of a C long.

Objects/longobject.c

@@ -3614,8 +3614,7 @@ long_rshift(PyLongObject *v, PyLongObject *w)
 {
 	PyLongObject *a, *b;
 	PyLongObject *z = NULL;
-	long shiftby;
-	Py_ssize_t newsize, wordshift, loshift, hishift, i, j;
+	Py_ssize_t shiftby, newsize, wordshift, loshift, hishift, i, j;
 	digit lomask, himask;
 
 	CONVERT_BINOP((PyObject *)v, (PyObject *)w, &a, &b);
@@ -3634,8 +3633,7 @@ long_rshift(PyLongObject *v, PyLongObject *w)
 		Py_DECREF(a2);
 	}
 	else {
-
-		shiftby = PyLong_AsLong((PyObject *)b);
+		shiftby = PyLong_AsSsize_t((PyObject *)b);
 		if (shiftby == -1L && PyErr_Occurred())
 			goto rshift_error;
 		if (shiftby < 0) {
@@ -3681,27 +3679,21 @@ long_lshift(PyObject *v, PyObject *w)
 	/* This version due to Tim Peters */
 	PyLongObject *a, *b;
 	PyLongObject *z = NULL;
-	long shiftby;
-	Py_ssize_t oldsize, newsize, wordshift, remshift, i, j;
+	Py_ssize_t shiftby, oldsize, newsize, wordshift, remshift, i, j;
 	twodigits accum;
 
 	CONVERT_BINOP(v, w, &a, &b);
 
-	shiftby = PyLong_AsLong((PyObject *)b);
+	shiftby = PyLong_AsSsize_t((PyObject *)b);
 	if (shiftby == -1L && PyErr_Occurred())
 		goto lshift_error;
 	if (shiftby < 0) {
 		PyErr_SetString(PyExc_ValueError, "negative shift count");
 		goto lshift_error;
 	}
-	if ((long)(int)shiftby != shiftby) {
-		PyErr_SetString(PyExc_ValueError,
-				"outrageous left shift count");
-		goto lshift_error;
-	}
 	/* wordshift, remshift = divmod(shiftby, PyLong_SHIFT) */
-	wordshift = (int)shiftby / PyLong_SHIFT;
-	remshift  = (int)shiftby - wordshift * PyLong_SHIFT;
+	wordshift = shiftby / PyLong_SHIFT;
+	remshift  = shiftby - wordshift * PyLong_SHIFT;
 
 	oldsize = ABS(a->ob_size);
 	newsize = oldsize + wordshift;