/usr/include/boost/thread/win32/ is in libboost1.62-dev 1.62.0+dfsg-5.
This file is owned by root:root, with mode 0o755.
..
/usr/include/boost/thread/win32/basic_recursive_mutex.hpp
/usr/include/boost/thread/win32/basic_timed_mutex.hpp
/usr/include/boost/thread/win32/condition_variable.hpp
/usr/include/boost/thread/win32/interlocked_read.hpp
/usr/include/boost/thread/win32/mfc_thread_init.hpp
/usr/include/boost/thread/win32/mutex.hpp
/usr/include/boost/thread/win32/once.hpp
/usr/include/boost/thread/win32/recursive_mutex.hpp
/usr/include/boost/thread/win32/shared_mutex.hpp
/usr/include/boost/thread/win32/thread_data.hpp
/usr/include/boost/thread/win32/thread_heap_alloc.hpp
/usr/include/boost/thread/win32/thread_primitives.hpp