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/Objects/complexobject.c

@@ -1,13 +1,11 @@
+/* clang-format off */
+#include "third_party/python/Include/Python.h"
+#include "third_party/python/Include/structmember.h"
 
 /* Complex object implementation */
-
 /* Borrows heavily from floatobject.c */
-
 /* Submitted by Jim Hugunin */
 
-#include "Python.h"
-#include "structmember.h"
-
 /* elementary operations on complex numbers */
 
 static Py_complex c_1 = {1., 0.};