Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1200

`backtrace` and `execinfo.h` can be provided by libexecinfo on uclibc and musl resulting in the following build failure with any user of abseil-cpp (such as collectd):

```
/home/buildroot/autobuild/instance-0/output-1/host/lib/gcc/sparc-buildroot-linux-uclibc/10.3.0/../../../../sparc-buildroot-linux-uclibc/bin/ld: /home/buildroot/autobuild/instance-0/output-1/host/bin/../sparc-buildroot-linux-uclibc/sysroot/usr/lib/libabsl_stacktrace.so: undefined reference to `backtrace'
```

[...]

```
    libgrpc++ . . . . . . no (libgrpc++ not found)
```

[...]

```
configure: error: "Some plugins are missing dependencies - see the summary above for details"
```

Fixes:
 - http://autobuild.buildroot.org/results/6a0484412f020e763ce3ad5bda48f09c78645bff

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Merge dac52cd20efb672278dc64bcd74920172a599ac0 into 93ad4284

Merging this change closes #1200

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1200 from ffontaine:master dac52cd20efb672278dc64bcd74920172a599ac0
PiperOrigin-RevId: 456323163
Change-Id: I3d2206761524d36e2b227c571e2e513f6840ff75

PiperOrigin-RevId: 456261906
Change-Id: I203199daa1687f54406be4583c2fd400bdbde2cd

As part of this update, GoogleTest is now using the Abseil flags
implementation, and the flags usage_test needs to be modified to pass.

If building with bazel and --define=absl=1 to force GoogleTest to use
Abseil, a WORKSPACE dependency on the abseil branch of the RE2 project
is now required.

PiperOrigin-RevId: 455512245
Change-Id: I2025df0c86006fac97a80713524c9d0aae8b358e

AnyInvocable is a C++11 compatible equivalent of the C++23 [std::move_only_function](https://en.cppreference.com/w/cpp/utility/functional/move_only_function/move_only_function).
Although this implementation matches an intermediate draft revision of the standard (http://wg21.link/p0288r5), it is neither a standard tracking type nor a seamless backfill type.

PiperOrigin-RevId: 455494585
Change-Id: If01565f8eecc78eee38fb794ef142b32b31abc7c

Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1197

Fix the following musl build failure on mips:

```
In file included from /nvmedata/autobuild/instance-15/output-1/build/libabseil-cpp-20211102.0/absl/base/internal/low_level_alloc.cc:26:
/nvmedata/autobuild/instance-15/output-1/build/libabseil-cpp-20211102.0/absl/base/internal/direct_mmap.h:49:10: fatal error: sgidefs.h: No such file or directory
   49 | #include <sgidefs.h>
      |          ^~~~~~~~~~~
```

Fixes:
 - http://autobuild.buildroot.org/results/3fa027e602bacb22316fb5d9b233baa0b0f0e845

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Merge c9b5b5c5471213a871f7d6d1d2fc8f6899effbac into a184bab8

Merging this change closes #1197

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1197 from ffontaine:master c9b5b5c5471213a871f7d6d1d2fc8f6899effbac
PiperOrigin-RevId: 455467767
Change-Id: I1905f7d70e914288bc1524a52adce3476a779fd8

PiperOrigin-RevId: 455463553
Change-Id: Ifa6c238556339dd4e36715ac040ca048f2f84a9a

Using GoogleTest at 0320f517fd920866d918e564105d68fd4362040a breaks Windows DLLs.

PiperOrigin-RevId: 455452411
Change-Id: Iff89a01351c01487786a22701efedf25860fadf9

As part of this update, GoogleTest is now using the Abseil flags
implementation, and the flags usage_test needs to be modified to pass.

If building with bazel and --define=absl=1 to force GoogleTest to use
Abseil, a WORKSPACE dependency on the abseil branch of the RE2 project
is now required.

PiperOrigin-RevId: 455257879
Change-Id: Id1548ce7d6a95b747b72a4f255d31ced98e36006

PiperOrigin-RevId: 455129922
Change-Id: I3b2a62cbf50057b3ea9b73c2edb44271dc46986c

since it has gotten worse in GCC 12

PiperOrigin-RevId: 455128070
Change-Id: Ia866e59d4e2e810aea16afe492d58013c5661a2b

Upstream bug report: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104336

PiperOrigin-RevId: 455001261
Change-Id: If0c72766a2a1d1e87c19c93c07cf62917031415b

PiperOrigin-RevId: 454969441
Change-Id: Ic18d91243ed3aa661ebf47a4c0ea96057aa4092d

PiperOrigin-RevId: 454947125
Change-Id: Idbe6c8b4953c3d6147326bebc915d24dff83e7d5

Upstream bug report: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105705

PiperOrigin-RevId: 454937873
Change-Id: I44f940caf36d83714af765f01cc43c5143fe21c3

PiperOrigin-RevId: 454934969
Change-Id: Ia4c157133e73ff16390179b37f7a789fc03fa92e

PiperOrigin-RevId: 454932630
Change-Id: Ifc716552bb0cd7babcaf416fe28462c15b4c7f23

contain the requested zone.

And now that we have a fallback at all, remove the special case that
allowed for testing absl::LocalTimeZone() under TZ=US/Pacific.

And we might as well update the existing embedded data while we're here.

This is modifying the test framework only.

PiperOrigin-RevId: 454896078
Change-Id: I3ec8391a5a51fe1e86a14f39d57ed6dac89d5905

PiperOrigin-RevId: 454305599
Change-Id: I528dfe0223280c379d8791373dc2871ad5812f63

PiperOrigin-RevId: 454251164
Change-Id: I256b7a662478f9317a4133ec209fa5488a942886

PiperOrigin-RevId: 454185620
Change-Id: Ifdff33cec4bdd63f160a8d3c18f959ac2a3b6f25

The intent of the macro is to say what locks cannot be held when calling the method, not making a promise that they will be acquired.

PiperOrigin-RevId: 454158686
Change-Id: I71087460c3df27c7d6e0571156f19f525024f1de

PiperOrigin-RevId: 453970585
Change-Id: Iac23eb88ea676efc822f001020b1cc2c255dbbc1

This change introduces the symbol
ABSL_INTERNAL_NEED_REDUNDANT_CONSTEXPR_DECL
to guard redundant declarations of static constexpr data
members that are needed prior to C++17.

This change also introduces the symbol
ABSL_INTERNAL_CPLUSPLUS_LANG, which is supposed to be set
to the same value as __cplusplus, except it uses _MSVC_LANG
on MSVC so that the value is correct on MSVC.

Neither of these new symbols should be used outside of Abseil.

Fixes #1191

PiperOrigin-RevId: 453923908
Change-Id: I1316c52c19fa0c168b93cced0c817e4cb7c9c862

https://pastebin.com/fDvgWgHe

After having a chat with Dougall Johnson (https://twitter.com/dougallj/status/1534213050944802816), we realized that __clzll works with zero arguments per documentation:

https://developer.arm.com/documentation/101028/0009/Data-processing-intrinsics

```
Returns the number of leading zero bits in x. When x is zero it returns the argument width, i.e. 32 or 64.
```

Codegen improves https://godbolt.org/z/ebadf717Y

Thus we can use a little bit different construction not involving CLS but using more understandable CLZ and removing some operations.

PiperOrigin-RevId: 453879080
Change-Id: Ie2d7f834f63364d7bd50dd6a682c107985f21942

PiperOrigin-RevId: 453766125
Change-Id: Id4d88ae20bdadc960a65bc1010eea746f1eba051

When we would perform a stacktrace using the frame pointer walking, because we
did the adjustment for the return address separately, we were misaligning the
stack size and frame.  Simplify the logic and correct the offset.

The recovered frame pointer provides us with the return address of the current
frame and the previous frame's frame pointer.  Subsequently, we decide if we
want to record this frame or not.  The value in `next_frame_pointer` already
points to the value from the previous stack frame (that is the next frame
pointer to iterate).  As such, the value computed by `ComputeStackFrameSize` is
the value for the current frame.  This was offset by one previously.

Take the opportunity to clean up some of the local comments, fixing typos and
splitting up the comments to reflect the lines that they are associated with.

PiperOrigin-RevId: 453744059
Change-Id: If14813e0ac36f327f4b7594472f2222d05c478aa

PiperOrigin-RevId: 453455549
Change-Id: Ib7c3d843d537e30d4086428dad539d162357308e

PiperOrigin-RevId: 453429588
Change-Id: Id377cd89dc807da80a33a8549f4e59bd935aff93

A few targets were missing `linkopts = ...` and so were not obeying
the project-wide default settings.

Omit any changes to cctz for now, because it's vendored from another project.

For portability, absl_time_test builds a small, incomplete tzdata
database into the test binary and uses that instead of the system tzdata
database. (absl_time_test needs to run on some platforms that lack a
system tzdata database.) However, this causes issues if TZ is set to
something that isn’t in the test database. To address them, fall back to
America/Los_Angeles if TZ is set to an unknown value during testing.

Bug: https://bugs.debian.org/1012194
PiperOrigin-RevId: 453257912
Change-Id: I293d0f96876b31c32a2847468a3377bb49f3aa15

CordBuffer::IncreaseLengthBy()

PiperOrigin-RevId: 453243686
Change-Id: If109da6be651006d4d9820bcc10eddfb56deaea2

PiperOrigin-RevId: 453241556
Change-Id: Ia92d737b6a678e3a4eda965056503392af44486a

Avoid using value move/swap and delete those functions from slot_policy types. There was only one use of params_type::move in `erase`.

PiperOrigin-RevId: 453237739
Change-Id: Ie81c6dba6c4db34e97a067d2c0defcded8044a5a

https://pastebin.com/CmnzwUFN

The key idea is to avoid using 16 byte NEON and use 8 byte NEON which has lower latency for BitMask::Match. Even though 16 byte NEON achieves higher throughput, in SwissMap it's very important to catch these Matches with low latency as probing on average happens at most once.

I also introduced NonIterableMask as ARM has really great cbnz instructions and additional AND on scalar mask had 1 extra latency cycle

PiperOrigin-RevId: 453216147
Change-Id: I842c50d323954f8383ae156491232ced55aacb78

absl::CordBuffer holds data for eventual inclusion within an existing
absl::Cord. CordBuffers are useful for building large Cords that may
require custom allocation of its associated memory, a pattern that is
common in zero-copy APIs.
PiperOrigin-RevId: 453212229
Change-Id: I6a8adc3a8d206691cb1b0001a9161e5080dd1c5f

Due to changes in GCC 12, without this change, the warning fires

PiperOrigin-RevId: 453197246
Change-Id: I2e31cbff1707ab09868cf77dcf040b033984e654

The "deleted" overload error is useless to users. By passing some dummy string to the base class constructor we use a valid constructor and remove the unintended use of the deleted default constructor.

PiperOrigin-RevId: 452826509
Change-Id: I5430a373c8e7e3a13336d2c42899e0e59444620b

PiperOrigin-RevId: 452619005
Change-Id: I6c120f9e7bbabe3b00821adc441608ae9118bee6

Include proper #includes for POSIX thread identity implementation when using that implementation on MinGW.

Fixes #1124

PiperOrigin-RevId: 452596638
Change-Id: Iab34b8e112dc050ffe346a418fa7b499983f0dcf

Decompose RandenPoolSeedSeq from NonsecureURBGBase.

Adjust how the RandenPoolSeedSeq detects contiguous buffers passed to the generate function. Previously it made incorrect assumptions regarding the contiguous concept, which have been replaced with some type-based tests for a small number of known contiguous random access iterator types, including raw pointers.

PiperOrigin-RevId: 452564114
Change-Id: Idab1df9dd078d8e5c565c7fa7ccb9c0d3d392ad2