bpo-36763: Add _PyInitError functions (GH-13395)

* Add _PyInitError functions:

  * _PyInitError_Ok()
  * _PyInitError_Error()
  * _PyInitError_NoMemory()
  * _PyInitError_Exit()
  * _PyInitError_IsError()
  * _PyInitError_IsExit()
  * _PyInitError_Failed()

* frozenmain.c and _testembed.c now use functions rather than macros.
* Move _Py_INIT_xxx() macros to the internal API.
* Move _PyWstrList_INIT macro to the internal API.
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index b40ecb7..4dad0b2 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -6,6 +6,7 @@
 
 #define PY_SSIZE_T_CLEAN
 #include <Python.h>
+#include "pycore_coreconfig.h"
 #include "pycore_object.h"
 #include "pycore_pymem.h"
 #include "pycore_pystate.h"
diff --git a/Objects/object.c b/Objects/object.c
index cb72794..604f5e0 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -2,6 +2,7 @@
 /* Generic object operations; and implementation of None */
 
 #include "Python.h"
+#include "pycore_coreconfig.h"
 #include "pycore_object.h"
 #include "pycore_pystate.h"
 #include "pycore_context.h"