Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1643

Addressing comments at https://github.com/abseil/abseil-cpp/pull/1604/#pullrequestreview-1937008657
Add a xcprivacy subspec and have all other subspecs depend on it (option 1)

Didn't going with option 3 because there are several levels of subspecs in abseil podspec, it's difficult to track whether all of them directly or indirectly depends on abseil/base/config or ensure they will continue to depend on it.

Example of generated podsped: https://gist.github.com/HannahShiSFB/15d8fb6aa637f2781b7be4218d080f11
Merge 4405cdfe71129bebb13c02a6d8ee18be7e813f73 into 4539c540

Merging this change closes #1643

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1643 from HannahShiSFB:privacy-manifests 4405cdfe71129bebb13c02a6d8ee18be7e813f73
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Change-Id: If56d5a4f1a7cc6f9fac7a2d8e95b55d140e645fc

The sampling rate may change over time, so this allows us to weight samples by
the value observed when we made the sampling decision.

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Change-Id: I9b1affdba93f5f48367cb7503916296b2d84709a

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Change-Id: I1ee813dd1b4da2d25d6b1b9cdba9e8f70d6a6d90

Add a feature to container_internal::Layout that lets you specify some array sizes at compile-time as template parameters. This can make offset and size calculations faster.

In particular, it seems to always improve the performance of AllocSize(), and it sometimes improves the performance of other functions, e.g. when the Layout object outlives the function that created it.

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Change-Id: Id1d318d7d2af68783f9f59090d89c642be6ae558

The workaround was added for a bug in GCC < 6.1., which had since been fixed. Abseil only [supports](https://github.com/google/oss-policies-info/blob/9a9bfe8a4a12be20757497074fc2f0ecb77438ad/foundational-cxx-support-matrix.md) GCC > 7.3.1.

However, removing the workaround still trips even more recent GCC, such as 13.1. When `SizeSeq` is empty, `p` is not actually used.
Marking it as `ABSL_ATTRIBUTE_UNUSED` silences the GCC warning for that case too.

We could disable `Slices` altogether when `SizeSeq` is empty, but that would be a breaking change (even though this API is internal), and possibly hurt generic programming use (they'd have to check if their parameter packs are empty).

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Change-Id: I77f7b0b921dfd63fb01c5223851ad1d8a7da233b

`layout`: Use auto return type for functions that explicitly instantiate std::tuple in return statements

This improves readability by avoiding spelling the same type twice, the first time with even more boilerplate (e.g. `typename`).
Return type deduction is a C++14 feature, and Abseil [currently supports](https://github.com/google/oss-policies-info/blob/9a9bfe8a4a12be20757497074fc2f0ecb77438ad/foundational-cxx-support-matrix.md) C++ >= 14.

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Change-Id: I3d69303d32431227c197247682f8dcb70f9a239d

No longer include vlog_is_on.h from log.h.  This is a breaking change.
To use VLOG_IS_ON(), absl/log/vlog_is_on.h must be included, not log.h.

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Change-Id: I59261eb5c28846557b43b040e187ec3ef36e4132

This change mainly affects 32-bit platforms. Similar to
4618865c, check for size_t overflow
in all places where string result sizes are precomputed before allocation.

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Change-Id: I71c774c5ef2c2978bd812c70e9bab36d266b7c90

This will allow us to give visibility to other Google-internal libraries. The
change is necessary since //visibility:private cannot be combined with other
specifications.

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Change-Id: I82b1edfa4e1ca280e429cf2a5e4003a1cc316a60

Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1603

Merge e324303b1f2aaee8e4418cffb838f150a2d4f4e7 into d8027081

Merging this change closes #1603

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1603 from adgajda:master e324303b1f2aaee8e4418cffb838f150a2d4f4e7
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Change-Id: Ia0e8211bd3c3d28fd0715c8f296ec50f6a700757

Roll back extern template instatiations in swisstable due to binary size increases in shared libraries.

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Change-Id: I5400b40a6bc5ac52ece5d4fa6da7df9e4ff50855

Motivation: mitigate linker input size increase from swisstable optimizations.

Note: the changes in raw_hash_set.h are fixing build errors that happened when adding the explicit instantiations. The change in unchecked_deref is because set iterators have const reference access whereas map iterators have mutable reference access and the function is never actually called for sets (it's used in raw_hash_map) so it wasn't needed before. I'm not sure why the soo_slot/soo_iterator problems didn't cause compile errors earlier.
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Change-Id: I7cc20a0129dcfbbddedd9e6d816bb6234bff14b3

GCC did not support <filesystem> until GCC8.

Fixes #1635

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Change-Id: I7c2143dd467e376eb4936ef894f3413bba681419

std:: equivalents

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Change-Id: Id6b1cffa4e104a82234130977235f1eb1021968f

Addition and subtraction operators std::array::iterator are defined only for
ptrdiff_t, which is signed, instead of size_t, which is unsigned. Therefore,
adding the index variable to ar.begin() will trigger -Wsign-conversion if
std::array::iterator is not a raw pointer because the index variable will be
implicitly converted from size_t (an unsigned type) to ptrdiff_t (a signed
type). To fix this, we explicitly static_cast index to a ptrdiff_t.
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Details:
- We use the space for control/slots pointers as the inline buffer.
- We use a max inline capacity of 1 to make the implementation much simpler and to avoid having to randomize the iteration order for inline tables.
- For iteration of inline tables, we introduce the kSooControl buffer which just has 1 full control byte followed by 1 sentinel control byte so that incrementing yields an end() iterator. We don't access kSooControl during lookups - only iteration.
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Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1632

Prior art for the `vector::erase` optimization:
https://github.com/AmadeusITGroup/amc/blob/efcb7be/include/amc/vectorcommon.hpp#L176-L180 https://github.com/bloomberg/bde/blob/e15f05be6/groups/bsl/bslalg/bslalg_arrayprimitives.h#L3787-L3799 https://github.com/facebook/folly/blob/d24bf04/folly/FBVector.h#L1254-L1262 https://github.com/qt/qtbase/blob/fbfee2d/src/corelib/tools/qarraydataops.h#L856-L861

Merge 6ce011079ccf945ae95434ce45ea6c5e3a088af8 into 55d28d4b

Merging this change closes #1632

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1632 from Quuxplusone:trivial-erase 6ce011079ccf945ae95434ce45ea6c5e3a088af8
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Change-Id: Ia9e7f146f5e1ecaffcb15de694049b716db38d02

* It is stated in prose that the methods on `absl::NoDestructor` can never return a null pointer
* Now this is annotated via nullability annotations as well

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Instead of casting an int to the enum type where the int does not have an associated enum value, cast the enum to its underlying type. This should be no functional change but make some linters happier.

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