* Disable inappropriate links to Python interpreter options
* Correct link to CLI section in zipapp
* Make CLI section label in timeit less ambiguous

enable link time optimizations at build time during a make profile-opt.

builds.  multiprocessing and subprocess tests in particular
along with test_asyncore and test_gdb.  Running them does not
meaningfully add to the profile guidance.

This has no semantic impact as the class is guarded with a hasattr()
check; this is being done to keep typing.py in sync between Python 3.5
and 3.6 as requested by Guido.

This affects documentation, code comments, and a debugging messages.

Thanks to Shaun Walbridge for noticing.

It can be seen on various buildbots like 3.x.cea-indiana-amd64
and 3.x.murray-snowleopard:

/export/home/buildbot/64bits/3.x.cea-indiana-amd64/build/Modules/_ssl.c:2227: warning: unused variable 'libver'

/Users/buildbot/buildarea/3.x.murray-snowleopard/build/Modules/_ssl.c:2227: warning: unused variable ‘libver’

NOTE: A direct call of super.__init__ is not endorsed!

syscall() function requires #include <unistd.h>.

Issue #26735: Fix os.urandom() on Solaris 11.3 and newer when reading more than
1,024 bytes: call getrandom() multiple times with a limit of 1024 bytes per
call.

Patch written by Demur Rumed.

Based on patch by Xiang Zhang.

Reported by Robert on docs@p.o.

The default value of __len__ is 0, not 1:

    >>> from unittest.mock import MagicMock
    >>> mock = MagicMock()
    >>> len(mock)
    0

Reported by Alex on docs@p.o.

Remove the remaining VMSError reference. VMS support is gone.

in places where Py_DECREF was used.

error handler for stdin and stdout.

Remove redundant tests now that str is unicode.

This eliminates a few redundant test cases.

* No longer attempts to close already freed socket file descriptor
* Use socket object to be compatible with Windows
* Do not use a timeout to avoid complication with non-blocking mode
* Use internal localhost server rather than depending on a third party
* Avoid trouble with buffered HTTP data by testing tunnelled CONNECT data