We cannot (yet) remove the EXPECTED_BOOST_INCLUDES entry as this header is still needed in fs.h (see #14763).
Partially reverts #14718.
This is required for some architectures.
utACK
utACK e816b341ab794fb84d89efb90b8c0f369d34d6ca
utACK e816b34
how did this get missed on review/testing?
Part of the problem is that apparantly Travis was down, and that wasn't noticed: #14763 (comment)