xrt: add explicit imports for standard C libraries
Recent versions of SDL2 have removed cstd lib
includes in interface header which causes compile errors
on some source files that were implicitly using
them.
Signed-off-by: Shiloh Fen <shiloh@shilohfen.com>
Co-authored-by: Torge Matthies <openglfreak@googlemail.com>
Co-authored-by: Korcan Hussein <korcan.hussein@collabora.com>
Part-of: <https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2409>