Abseil LTS branch, Jan 2026, Patch 1 (abseil#2007)

* Fix sign-extension issue in absl::HexStringToBytes()
* Restrict MSVC CRC32 intrinsics to x64.

Abseil LTS branch, Aug 2025, Patch 2 (abseil#2008)

* Fix sign-extension issue in absl::HexStringToBytes()

Abseil LTS branch, May 2025, Patch 2 (abseil#2009)

* Fix sign-extension issue in absl::HexStringToBytes()

Abseil LTS branch, Jan 2025, Patch 2 (abseil#2010)

* Fix sign-extension issue in absl::HexStringToBytes()

Abseil LTS branch, July 2024, Patch 2 (abseil#2011)

* Fix sign-extension issue in absl::HexStringToBytes()

Cherry-picks for LTS 20260107 (abseil#1990)

* Fix unused variable warning in GCC7

PiperOrigin-RevId: 853321697
Change-Id: I44b09e10e6ca1bb9b9f30a01a0f5acd5923371c1

* Fix self-move handling in absl::linked_hash_{set|map}

PiperOrigin-RevId: 853340964
Change-Id: I818695f01d53b5515be24122e1988e69ad6421d4

Cherry-picks for LTS 20260107 (abseil#1990)

* Fix unused variable warning in GCC7

PiperOrigin-RevId: 853321697
Change-Id: I44b09e10e6ca1bb9b9f30a01a0f5acd5923371c1

* Fix self-move handling in absl::linked_hash_{set|map}

PiperOrigin-RevId: 853340964
Change-Id: I818695f01d53b5515be24122e1988e69ad6421d4

Apply LTS transformations for 20260107 LTS branch (abseil#1989)

Abseil LTS branch, Aug 2025, Patch 1 (abseil#1940)

* Fix CHECK_<OP> ambiguous overload for operator<< in older versions of GCC (ba9a180)
* Fix CHECK_<OP> compilation failures on older versions of GCC which eagerly tries to instantiate std::underlying_type for non-enum types (e8c1a5f)
* Add missing rules_cc loads (2370ccf)

Apply LTS transformations for 20250814 LTS branch (abseil#1920)