Issue #14521: Make result of float('nan') and float('-nan') more consistent across platforms.  Further, don't rely on Py_HUGE_VAL for float('inf').

 * 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.

Use time.perf_counter() or time.process_time() instead.

 * Rename time.steady() to time.monotonic()
 * On Windows, time.monotonic() uses GetTickCount/GetTickCount64() instead of
   QueryPerformanceCounter()
 * time.monotonic() uses CLOCK_HIGHRES if available
 * Add time.get_clock_info(), time.perf_counter() and time.process_time()
   functions

not always available.

Also, block delivery of signals to that thread. Patch by Richard Oudkerk.

This will hopefully fix sporadic freezes on the FreeBSD 9.0 buildbot.

 * Remove _PyBytes_FormatLong(): inline it into formatlong()
 * the input type is always a long, so remove the code for bool
 * don't duplicate the string if the length does not change
 * Use PyUnicode_DATA() instead of _PyUnicode_AsString()

importlib.util.module_for_loader also will set __loader__ along with
__package__. This is in conjunction to a forthcoming update to PEP 302
which will make these two attributes required for loaders to set.

finder instead of using some (now non-existent) implicit finder.