Export of internal Abseil changes

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642ab296a2c9629c44f3f2ce6911cd2488bcf416 by Derek Mauro <dmauro@google.com>:

Remove an obsolete check in CMakeLists.txt

PiperOrigin-RevId: 352852564

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ce78cb96bcfd162737dbcf35005da3d1d6a3486b by Abseil Team <absl-team@google.com>:

Clarify that the calling *thread* must have locked the mutex in order to unlock
it.

PiperOrigin-RevId: 352801804

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24e1f5f72756046f5265abf618e951c341f09b8d by Derek Mauro <dmauro@google.com>:

Fixes failing CMake string comparisons
https://cmake.org/cmake/help/latest/policy/CMP0054.html

Fixes #791

PiperOrigin-RevId: 352791054

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0ac10bc3f4dca2c4c4b51d7b8196a2eaee9537a1 by Abseil Team <absl-team@google.com>:

Introduce CordRepRing class

This change introduces the CordRepRing class that implements all the lower level / internal implementation for upcoming CordRepRing ring buffer support in cord.

PiperOrigin-RevId: 352771994

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4bd36dda61760785844f0f29f26d90cc18046f75 by Abseil Team <absl-team@google.com>:

Optimize InlineData representation for cord sampling (cordz)

This CL changes InlineData to allow us to store a (future) Cordz Info pointer directly into the inline representation:

- make InlineData a class that provides a public API to set the active union members (tree or chars) and safely access that data.
- change 'tree' and 'profiled' bits to be the 2 least significant bits, allowing us 62 continquous bits for storing a Cordz Info pointer.

PiperOrigin-RevId: 352642411

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dc55ba71bbce0e6a83e05a453990c51ac3d68426 by Mark Barolak <mbar@google.com>:

Add unit test coverage for the mutating overload of absl::AsciiStrToLower.

PiperOrigin-RevId: 352626006
GitOrigin-RevId: 642ab296a2c9629c44f3f2ce6911cd2488bcf416
Change-Id: I6c5929dd830d3c630e14e7fd5387fc3e25a69100

1 files changed, 1 insertions, 1 deletions

diff --git a/absl/synchronization/mutex.h b/absl/synchronization/mutex.h
index 598d1e06..4dd51fec 100644
--- a/absl/synchronization/mutex.h
+++ b/absl/synchronization/mutex.h
@@ -162,7 +162,7 @@ class ABSL_LOCKABLE Mutex {
   // Mutex::Unlock()
   //
   // Releases this `Mutex` and returns it from the exclusive/write state to the
-  // free state. Caller must hold the `Mutex` exclusively.
+  // free state. Calling thread must hold the `Mutex` exclusively.
   void Unlock() ABSL_UNLOCK_FUNCTION();
 
   // Mutex::TryLock()