Adds bounds-checking to the second range of absl container algorithms (…

…abseil#812)

The APIs for the two-range `absl::c_mismatch`, `absl::c_swap_ranges`,
and `absl::c_transform` are misleading as they do not check the bounds
of the second range against the first one.

This commit cleans up ensures that buggy calls are not exploitable;
non-buggy calls are unaffected.

This is consistent with both C++14's two-range `std::` equivalents and
C++20's `std::ranges::` equivalents.
http://wg21.link/mismatch
http://wg21.link/alg.swap
http://wg21.link/alg.transform

Adds bounds-checking to the second range of absl container algorithms (…

…abseil#813)

The APIs for the two-range `absl::c_mismatch`, `absl::c_swap_ranges`,
and `absl::c_transform` are misleading as they do not check the bounds
of the second range against the first one.

This commit cleans up ensures that buggy calls are not exploitable;
non-buggy calls are unaffected.

This is consistent with both C++14's two-range `std::` equivalents and
C++20's `std::ranges::` equivalents.
http://wg21.link/mismatch
http://wg21.link/alg.swap
http://wg21.link/alg.transform

Add 20200923 tag

Fix undefined symbol in MacOS dylib by adding absl::string dependency…

… to absl::cord as proposed by moubctez on issue abseil#624 (abseil#670)

Patch LTS with the bug fix for `absl::Status::ErasePayload`. (abseil#632

)

f8fe7bd53bfed601f002f521e34ab4bc083fc28b by Matthew Brown <matthewbr@google.com>:

Ensure a deep copy and proper equality on absl::Status::ErasePayload

PiperOrigin-RevId: 298482742

Abseil LTS branch, February 2020

Abseil LTS branch, August 2019

Abseil LTS branch, December 2018

Abseil LTS branch, June 2018