--
69b3ab092ee0fef3d27f589e709280c341f006c6 by Greg Falcon <gfalcon@google.com>:

Import of CCTZ from GitHub.

PiperOrigin-RevId: 321005878

--
3a4038cd0cea6455453a7ae82f2de7e91d7e2bc1 by Abseil Team <absl-team@google.com>:

Google-internal changes only.

PiperOrigin-RevId: 320994821

--
f9d9a93782924df6ffc351a271c239ca4bdff3c8 by Derek Mauro <dmauro@google.com>:

Update Linux latest toolchains, most notably to GCC 10.1

This create a new "hybrid" docker image that includes the latest
versions of both GCC and LLVM. Since the LLVM build targets Debian 10,
but Debian 10 uses an older version of libstdc++ that doesn't have
full C++20 support, the easiest solution is to use the GCC/Debian 10
base image from DockerHub and copy LLVM into it.

This also includes fixes to get the build working with the
new toolchains.

PiperOrigin-RevId: 320991795

--
43129cd66dc4439b36d85030800a3929f20d9f86 by Abseil Team <absl-team@google.com>:

Rollback import of CCTZ from GitHub (breaks MSAN tests)

  - e87b391f0d10ae9c3d2e70e4a3633337d2c5e643 handle "slim" TZif files in TimeZoneInfo::ExtendTransitio... by Bradley White <14679271+devbww@users.noreply.github.com>

PiperOrigin-RevId: 320978767

--
2a343a55f297d433c1521920f0bd20ddd2dc71e8 by Derek Mauro <dmauro@google.com>:

Use ABSL_HAVE_ATTRIBUTE in thread_annotations.h

PiperOrigin-RevId: 320956378

--
f6f3e8333c9ef6e6441586be6587bbfb1c8c8127 by Gennadiy Rozental <rogeeff@google.com>:

Import of CCTZ from GitHub.

PiperOrigin-RevId: 320952592

--
3cc2bcce3533ac1233c0536232b07eea45fe8ed0 by Derek Mauro <dmauro@google.com>:

Internal change

PiperOrigin-RevId: 320862698

--
4e22066476744609e42c475b55e3cbd874f04c39 by Gennadiy Rozental <rogeeff@google.com>:

Internal change

PiperOrigin-RevId: 320461277
GitOrigin-RevId: 69b3ab092ee0fef3d27f589e709280c341f006c6
Change-Id: I36f547711e7078d52f2e0a1ff3f4c903056a2b9e