OpenImageViewer requires all of these functions for the file information menu to work.
This implementation references the open-source (Apache 2.0) STL code: https://github.com/microsoft/STL/blob/main/stl/src/tzdb.cpp
-- v2: msvcp140_atomic_wait/tests: Add tests for the __std_tzdb functions. msvcp140_atomic_wait: Partially implement __std_tzdb_*_leap_seconds().