Perform build and magnum tuning

Building o//third_party/python now takes 5 seconds on my PC

This change works towards modifying Python to use runtime dispatching
when appropriate. For example, when loading the magnums in the socket
module, it's a good idea to check if the magnum is zero, because that
means the local system platform doesn't support it.

third_party/python/Modules/clinic/grpmodule.inc

@@ -0,0 +1,90 @@
+/* clang-format off */
+/*[clinic input]
+preserve
+[clinic start generated code]*/
+
+PyDoc_STRVAR(grp_getgrgid__doc__,
+"getgrgid($module, /, id)\n"
+"--\n"
+"\n"
+"Return the group database entry for the given numeric group ID.\n"
+"\n"
+"If id is not valid, raise KeyError.");
+
+#define GRP_GETGRGID_METHODDEF    \
+    {"getgrgid", (PyCFunction)grp_getgrgid, METH_FASTCALL, grp_getgrgid__doc__},
+
+static PyObject *
+grp_getgrgid_impl(PyObject *module, PyObject *id);
+
+static PyObject *
+grp_getgrgid(PyObject *module, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    static const char * const _keywords[] = {"id", NULL};
+    static _PyArg_Parser _parser = {"O:getgrgid", _keywords, 0};
+    PyObject *id;
+
+    if (!_PyArg_ParseStack(args, nargs, kwnames, &_parser,
+        &id)) {
+        goto exit;
+    }
+    return_value = grp_getgrgid_impl(module, id);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(grp_getgrnam__doc__,
+"getgrnam($module, /, name)\n"
+"--\n"
+"\n"
+"Return the group database entry for the given group name.\n"
+"\n"
+"If name is not valid, raise KeyError.");
+
+#define GRP_GETGRNAM_METHODDEF    \
+    {"getgrnam", (PyCFunction)grp_getgrnam, METH_FASTCALL, grp_getgrnam__doc__},
+
+static PyObject *
+grp_getgrnam_impl(PyObject *module, PyObject *name);
+
+static PyObject *
+grp_getgrnam(PyObject *module, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    static const char * const _keywords[] = {"name", NULL};
+    static _PyArg_Parser _parser = {"U:getgrnam", _keywords, 0};
+    PyObject *name;
+
+    if (!_PyArg_ParseStack(args, nargs, kwnames, &_parser,
+        &name)) {
+        goto exit;
+    }
+    return_value = grp_getgrnam_impl(module, name);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(grp_getgrall__doc__,
+"getgrall($module, /)\n"
+"--\n"
+"\n"
+"Return a list of all available group entries, in arbitrary order.\n"
+"\n"
+"An entry whose name starts with \'+\' or \'-\' represents an instruction\n"
+"to use YP/NIS and may not be accessible via getgrnam or getgrgid.");
+
+#define GRP_GETGRALL_METHODDEF    \
+    {"getgrall", (PyCFunction)grp_getgrall, METH_NOARGS, grp_getgrall__doc__},
+
+static PyObject *
+grp_getgrall_impl(PyObject *module);
+
+static PyObject *
+grp_getgrall(PyObject *module, PyObject *Py_UNUSED(ignored))
+{
+    return grp_getgrall_impl(module);
+}
+/*[clinic end generated code: output=d6417ae0a7298e0e input=a9049054013a1b77]*/