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/fileobject.c

@@ -1,7 +1,8 @@
+/* clang-format off */
 /* File object implementation (what's left of it -- see io.py) */
 
 #define PY_SSIZE_T_CLEAN
-#include "Python.h"
+#include "third_party/python/Include/Python.h"
 #include "libc/stdio/unlocked.h"
 
 #if defined(HAVE_GETC_UNLOCKED) && !defined(_Py_MEMORY_SANITIZER)
@@ -21,10 +22,6 @@
 #define NEWLINE_LF 2            /* \n newline seen */
 #define NEWLINE_CRLF 4          /* \r\n newline seen */
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /* External C interface */
 
 PyObject *
@@ -525,8 +522,3 @@ PyTypeObject PyStdPrinter_Type = {
     stdprinter_new,                             /* tp_new */
     PyObject_Del,                               /* tp_free */
 };
-
-
-#ifdef __cplusplus
-}
-#endif