Issue #14428: Use the new time.perf_counter() and time.process_time() functions

 * Replace "time.clock on windows, or time.time" with time.perf_counter()
 * profile module: only use time.process_time() instead of trying different
   functions providing the process time
 * timeit module: use time.perf_counter() by default, time.time() and
   time.clock() can still be used using --time and --clock options
 * pybench program: use time.perf_counter() by default, add support for
   the new time.process_time() and time.perf_counter() functions, but stay
   backward compatible. Use also time.get_clock_info() to display information
   of the timer.
diff --git a/Doc/includes/mp_benchmarks.py b/Doc/includes/mp_benchmarks.py
index acdf642..3763ea9 100644
--- a/Doc/includes/mp_benchmarks.py
+++ b/Doc/includes/mp_benchmarks.py
@@ -6,16 +6,12 @@
 #
 
 import time
-import sys
 import multiprocessing
 import threading
 import queue
 import gc
 
-if sys.platform == 'win32':
-    _timer = time.clock
-else:
-    _timer = time.time
+_timer = time.perf_counter
 
 delta = 1