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/pwdmodule.inc

@@ -0,0 +1,73 @@
+/* clang-format off */
+/*[clinic input]
+preserve
+[clinic start generated code]*/
+
+PyDoc_STRVAR(pwd_getpwuid__doc__,
+"getpwuid($module, uidobj, /)\n"
+"--\n"
+"\n"
+"Return the password database entry for the given numeric user ID.\n"
+"\n"
+"See `help(pwd)` for more on password database entries.");
+
+#define PWD_GETPWUID_METHODDEF    \
+    {"getpwuid", (PyCFunction)pwd_getpwuid, METH_O, pwd_getpwuid__doc__},
+
+PyDoc_STRVAR(pwd_getpwnam__doc__,
+"getpwnam($module, arg, /)\n"
+"--\n"
+"\n"
+"Return the password database entry for the given user name.\n"
+"\n"
+"See `help(pwd)` for more on password database entries.");
+
+#define PWD_GETPWNAM_METHODDEF    \
+    {"getpwnam", (PyCFunction)pwd_getpwnam, METH_O, pwd_getpwnam__doc__},
+
+static PyObject *
+pwd_getpwnam_impl(PyObject *module, PyObject *arg);
+
+static PyObject *
+pwd_getpwnam(PyObject *module, PyObject *arg_)
+{
+    PyObject *return_value = NULL;
+    PyObject *arg;
+
+    if (!PyArg_Parse(arg_, "U:getpwnam", &arg)) {
+        goto exit;
+    }
+    return_value = pwd_getpwnam_impl(module, arg);
+
+exit:
+    return return_value;
+}
+
+#if defined(HAVE_GETPWENT)
+
+PyDoc_STRVAR(pwd_getpwall__doc__,
+"getpwall($module, /)\n"
+"--\n"
+"\n"
+"Return a list of all available password database entries, in arbitrary order.\n"
+"\n"
+"See help(pwd) for more on password database entries.");
+
+#define PWD_GETPWALL_METHODDEF    \
+    {"getpwall", (PyCFunction)pwd_getpwall, METH_NOARGS, pwd_getpwall__doc__},
+
+static PyObject *
+pwd_getpwall_impl(PyObject *module);
+
+static PyObject *
+pwd_getpwall(PyObject *module, PyObject *Py_UNUSED(ignored))
+{
+    return pwd_getpwall_impl(module);
+}
+
+#endif /* defined(HAVE_GETPWENT) */
+
+#ifndef PWD_GETPWALL_METHODDEF
+    #define PWD_GETPWALL_METHODDEF
+#endif /* !defined(PWD_GETPWALL_METHODDEF) */
+/*[clinic end generated code: output=fc41d8d88ec206d8 input=a9049054013a1b77]*/