thread_local is supported on all supported platforms https://github.com/google/oss-policies-info/blob/main/foundational-cxx-support-matrix.md ABSL_HAVE_THREAD_LOCAL should be considered deprecated at this point. PiperOrigin-RevId: 639029951 Change-Id: I6525766c428f897fa50148e5c6b5a0f3fff0d9be
