regrtest -W hides output if a test pass, but also when env changed and so the
env changed warning is hidden. So it's hard to debug. With this change, stderr
is now always displayed when a test doesn't pass.

The code was correct, but GCC is not enough clever.

unscathed to the C-defined function.  Now it is converted to exact tuple.

This fixes a regression caused by revision 73afda5a4e4c. Also reverts the
decimal test workaround added in revision 5f3dd0a2b1ab.

Remove test_without_exception(). According to revision ecaafc32c500, this was
added in Python 2 so that print_exc() would output “None” when called with no
exception set. However print_exc() never worked like this in Python 3, and
the use case is not documented.

Restore TracebackCases class name (instead of SyntaxTracebackCases), because
the class also tests other exceptions.

instance.

Issue #28233: Fix a memory leak if the format string contains a non-ASCII
character, destroy the unicode writer.

Issue #28176: Increase timeout from 10 seconds to 60 seconds.

Issue #27778: Fix a memory leak in os.getrandom() when the getrandom() is
interrupted by a signal and a signal handler raises a Python exception.

Modify also os_getrandom_impl() to avoid the temporary buffer, use directly a
Python bytes object.

Issue #27955: Fallback on reading /dev/urandom device when the getrandom()
syscall fails with EPERM, for example when blocked by SECCOMP.

Issue #27955: Fallback on reading /dev/urandom device when the getrandom()
syscall fails with EPERM, for example when blocked by SECCOMP.

Issue #27955: modify py_getrnadom() and dev_urandom()

* Add comments from Python 3.7
* PEP 7 style: add {...}