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/Lib/test/reperf.py b/Lib/test/reperf.py
index 7c68234..e93bacd 100644
--- a/Lib/test/reperf.py
+++ b/Lib/test/reperf.py
@@ -9,13 +9,13 @@
     timefunc(10, p.findall, s)
 
 def timefunc(n, func, *args, **kw):
-    t0 = time.clock()
+    t0 = time.perf_counter()
     try:
         for i in range(n):
             result = func(*args, **kw)
         return result
     finally:
-        t1 = time.clock()
+        t1 = time.perf_counter()
         if n > 1:
             print(n, "times", end=' ')
         print(func.__name__, "%.3f" % (t1-t0), "CPU seconds")