Roll libc++ from 9b27200e8219 to 7c70886f2550 (13 revisions)

https://chromium.googlesource.com/external/github.com/llvm/llvm-project/libcxx.git/+log/9b27200e8219..7c70886f2550

2023-10-27 ldionne.2@gmail.com [libc++] Fix incorrect length check in std::basic_filebuf
2023-10-27 ldionne.2@gmail.com [libc++] Make sure we implement and test LWG2280 properly (#67670)
2023-10-27 var-const@users.noreply.github.com [libc++] Fix flakiness in `atomic_notify_all.pass.cpp` (#70436)
2023-10-27 rajveer.developer@icloud.com [libc++] Fix _CopySegment helper in ranges::copy(join_view, out) when called in a static assertion context (#69593)
2023-10-27 vitalybuka@google.com Revert "[libc++][tests] Fix a few remaining instances of outdated static assertion regexes in our test suite"
2023-10-27 vitalybuka@google.com Fix typo in c07903aac7b9bc60d48f0381073285d79642cc3f
2023-10-27 vitalybuka@google.com [libc++abi] Disable test with a leaks
2023-10-26 zhangyin2018@iscas.ac.cn [libc++] <experimental/simd> Add assignment operator of simd reference (#70020)
2023-10-26 ldionne.2@gmail.com [libc++][NFC] Remove unused typedefs in filesystem::path helpers (#70331)
2023-10-26 tokarip@google.com [libc++] Optimize string operator[] for known large inputs (#69500)
2023-10-26 ldionne.2@gmail.com [libc++][tests] Fix a few remaining instances of outdated static assertion regexes in our test suite
2023-10-26 fsb4000@yandex.ru [libc++] Make sure std::declval() produces an error when ODR-used
2023-10-26 nikolasklauser@berlin.de [libc++] Add __small_buffer

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/libcxx-chromium
Please CC hans@chromium.org,thakis@chromium.org on the revert to ensure that a human
is aware of the problem.

To file a bug in Chromium: https://bugs.chromium.org/p/chromium/issues/entry

To report a problem with the AutoRoller itself, please file a bug:
https://issues.skia.org/issues/new?component=1389291&template=1850622

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

Tbr: hans@chromium.org,thakis@chromium.org
Change-Id: I371e06cc9aad630a337202619522305bc2b870fe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4984702
Bot-Commit: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1216245}

diff --git a/DEPS b/DEPS
index 74bae941..a9fbd3b 100644
--- a/DEPS
+++ b/DEPS

@@ -524,7 +524,7 @@
 
   # If you change this, also update the libc++ revision in
   # //buildtools/deps_revisions.gni.
-  'libcxx_revision':       '9b27200e8219bbc9e05ba8435456554a6e35d67d',
+  'libcxx_revision':       '7c70886f25508b03921d9fba54d96e49809d9131',
 
   # GN CIPD package version.
   'gn_version': 'git_revision:e4702d7409069c4f12d45ea7b7f0890717ca3f4b',

diff --git a/buildtools/deps_revisions.gni b/buildtools/deps_revisions.gni
index e491e122..9bf55da3 100644
--- a/buildtools/deps_revisions.gni
+++ b/buildtools/deps_revisions.gni

@@ -5,5 +5,5 @@
 declare_args() {
   # Used to cause full rebuilds on libc++ rolls. This should be kept in sync
   # with the libcxx_revision vars in //DEPS.
-  libcxx_revision = "9b27200e8219bbc9e05ba8435456554a6e35d67d"
+  libcxx_revision = "7c70886f25508b03921d9fba54d96e49809d9131"
 }

diff --git a/third_party/libc++/src b/third_party/libc++/src
index 9b27200..7c70886 160000
--- a/third_party/libc++/src
+++ b/third_party/libc++/src

@@ -1 +1 @@
-Subproject commit 9b27200e8219bbc9e05ba8435456554a6e35d67d
+Subproject commit 7c70886f25508b03921d9fba54d96e49809d9131