bpo-44353: Implement typing.NewType __call__ method in C (#27262)

Co-authored-by: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Co-authored-by: Denis Laxalde <denis@laxalde.org>

Modules/_typingmodule.c

@@ -0,0 +1,59 @@
+/* typing accelerator C extension: _typing module. */
+
+#include "Python.h"
+#include "clinic/_typingmodule.c.h"
+
+/*[clinic input]
+module _typing
+
+[clinic start generated code]*/
+/*[clinic end generated code: output=da39a3ee5e6b4b0d input=1db35baf1c72942b]*/
+
+/* helper function to make typing.NewType.__call__ method faster */
+
+/*[clinic input]
+_typing._idfunc -> object
+
+    x: object
+    /
+
+[clinic start generated code]*/
+
+static PyObject *
+_typing__idfunc(PyObject *module, PyObject *x)
+/*[clinic end generated code: output=63c38be4a6ec5f2c input=49f17284b43de451]*/
+{
+    Py_INCREF(x);
+    return x;
+}
+
+
+static PyMethodDef typing_methods[] = {
+    _TYPING__IDFUNC_METHODDEF
+    {NULL, NULL, 0, NULL}
+};
+
+PyDoc_STRVAR(typing_doc,
+"Accelerators for the typing module.\n");
+
+static struct PyModuleDef_Slot _typingmodule_slots[] = {
+    {0, NULL}
+};
+
+static struct PyModuleDef typingmodule = {
+        PyModuleDef_HEAD_INIT,
+        "_typing",
+        typing_doc,
+        0,
+        typing_methods,
+        _typingmodule_slots,
+        NULL,
+        NULL,
+        NULL
+};
+
+PyMODINIT_FUNC
+PyInit__typing(void)
+{
+    return PyModuleDef_Init(&typingmodule);
+}