Issue #22043: _PyTime_Init() now checks if the system clock works.

Other changes:

* The whole _PyTime API is private (not defined if Py_LIMITED_API is set)
* _PyTime_gettimeofday_info() also returns -1 on error
* Simplify PyTime_gettimeofday(): only use clock_gettime(CLOCK_REALTIME) or
  gettimeofday() on UNIX. Don't fallback to ftime() or time() anymore.
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 63d9eeb..bac39c2 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -452,7 +452,8 @@
     if (_PyFaulthandler_Init())
         Py_FatalError("Py_Initialize: can't initialize faulthandler");
 
-    _PyTime_Init();
+    if (_PyTime_Init() < 0)
+        Py_FatalError("Py_Initialize: can't initialize time");
 
     if (initfsencoding(interp) < 0)
         Py_FatalError("Py_Initialize: unable to load the file system codec");