"ours" merge to avoid picking up 0.2.9 version of ticket 31673.

tor_isinf() was new in 0.4.0, and also needs to look at the
same rules as clamp_double_to_i64()

Our code assumes that when we're configured to get IPv6 addresses
out of a TRANS_PF transparent proxy connection, we actually will.
But we didn't check that, and so FreeBSD started warning us about a
potential NULL pointer dereference.

Fixes part of bug 31687; bugfix on 0.2.3.4-alpha when this code was
added.

We used to do this on Windows only, but it appears to affect
multiple platforms when building with certain versions of GCC, and a
common pattern for defining the floating-point classifier functions.

Fixes part of 31687. I'm calling this a bugfux on 31687, when we
started suppressing these warnings on Windows.

Closes #31673

Closes #31673

When tor is missing descriptors for some primary entry guards, make the
log message less alarming. It's normal for descriptors to expire, as long
as tor fetches new ones soon after.

Fixes bug 31657; bugfix on 0.3.3.1-alpha.

tor-github/pr/1174, but with the last commit re-worded to remove
the fixup, because fixups break our push rules.

This change makes test-stem faster and more reliable.

Use "make test-stem-full" to run all of stem's tests.

Closes ticket 31554.

Sebastian Hahn authored Aug 20, 2019 and teor committed Aug 22, 2019

The main build doesn't use HARDENING_OPTIONS, so the exclude shouldn't,
either. Reduces the number of builders by one.

New IP address from 194.109.206.212 to 45.66.33.45.

Signed request from Alex de Joode, operator of dizum:
https://trac.torproject.org/projects/tor/ticket/31406



Published descriptor by dizum on August 12th, 2019:

--
r dizum fqbq1v2DCDxTj0QDi7+gd1h911U GZmZtCLaPDQNxkhIFj8UcgTRAuA 2019-08-12 15:28:40 45.66.33.45 443 80
s Authority Fast Running Stable V2Dir Valid
v Tor 0.4.0.5
pr Cons=1-2 Desc=1-2 DirCache=1-2 HSDir=1-2 HSIntro=3-4 HSRend=1-2 Link=1-5 LinkAuth=1,3 Microdesc=1-2 Relay=1-2 Padding=1
w Bandwidth=20 Unmeasured=1
p reject 1-65535
--

Finally, confirmed by DNS:

  $ dig +short tor.dizum.com
  45.66.33.45

Closes #31406

Signed-off-by: David Goulet <dgoulet@torproject.org>