Without this patch, `ninja check` on upgrade-activated unit tests will fail
because the behavior subtly changed to require a `--` between BOOST test module arguments
and custom arguments. Versions of boost > 1.58 fail.
Earliest documentation I could find that references this behavior: https://www.boost.org/doc/libs/1_70_0/libs/test/doc/html/boost_test/runtime_config/custom_command_line_arguments.html