* Change __BORLANDC__ to BOOST_BORLANDC, which is defined in Boost config for the Embarcadero non-clang-based compilers.
* More changes of __BORLANDC__ to BOOST_BORLANDC, which is defined in Boost config for the Embarcadero non-clang-based compilers.
* Embarcadero C++ clang-based compilers use chdir instead of _chdir on Windows. This was reported to them as a bug.
* Revert "Embarcadero C++ clang-based compilers use chdir instead of _chdir on Windows. This was reported to them as a bug."
This reverts commit d00a21f736.
* Put back the chdir definition change to exclude Embarcadero clang-based compilers.