add PySeqIter_New

Author: timfel

graalpython/com.oracle.graal.python.cext/src/iterobject.c

@@ -0,0 +1,9 @@
+#include "capi.h"
+
+PyObject* PySeqIter_New(PyObject *seq) {
+    if (!PySequence_Check(seq)) {
+        PyErr_BadInternalCall();
+        return NULL;
+    }
+    return UPCALL_O(PY_BUILTIN, "iter", native_to_java(seq));
+}