This should fix readdir(_r) on 32-bit systems, which was not 64-bit after
commit c758552338 because _FILE_OFFSET_BITS=64
was not defined in directory.cpp. Also, there were filesystem-related system
calls in unique_path.cpp, where the macro was not defined either. Including
the platform header in all source files is useful for possible future changes
that may require the platform-specific macros.
Closes https://github.com/boostorg/filesystem/pull/150.
This simplifies maintenance of the operations.hpp/cpp files.
Also, moved BOOST_FILESYSTEM_SOURCE definition to the build system files
instead of defining it in every source file.
Switched directory_iterator and recursive_directory_iterator to use
intrusive_ptr internally to reduce the iterator size and avoid virtual
function calls. The iterators now support move semantics. Fixed a warning
about deprecated in C++20 implicit generation of copy constructor and
assignment operator if there is a user-defined destructor.
Also updated a few includes to refer to non-deprecated headers. Trimmed
trailing spaces in headers and sources.
