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/Include/pylifecycle.h

@@ -1,11 +1,7 @@
-
-/* Interfaces to configure, query, create & destroy the Python runtime */
-
 #ifndef Py_PYLIFECYCLE_H
 #define Py_PYLIFECYCLE_H
-#ifdef __cplusplus
-extern "C" {
-#endif
+COSMOPOLITAN_C_START_
+/* clang-format off */
 
 PyAPI_FUNC(void) Py_SetProgramName(wchar_t *);
 PyAPI_FUNC(wchar_t *) Py_GetProgramName(void);
@@ -125,7 +121,5 @@ PyAPI_FUNC(int) _PyOS_URandom(void *buffer, Py_ssize_t size);
 PyAPI_FUNC(int) _PyOS_URandomNonblock(void *buffer, Py_ssize_t size);
 #endif /* !Py_LIMITED_API */
 
-#ifdef __cplusplus
-}
-#endif
+COSMOPOLITAN_C_END_
 #endif /* !Py_PYLIFECYCLE_H */