Silence warnings for system headers that we or third_party transitively includes.
Silence warnings for system headers that we or third_party transitively includes.

GCC with link time optimizations does not to respect this mode
unfortunately, reuslting in warnings in release (default) build
mode from system includes such as boost, luabind and so on.

bjtaylor1/osrm-backend,raymond0/osrm-backend,hydrays/osrm-backend,Project-OSRM/osrm-backend,KnockSoftware/osrm-backend,KnockSoftware/osrm-backend,yuryleb/osrm-backend,duizendnegen/osrm-backend,raymond0/osrm-backend,yuryleb/osrm-backend,KnockSoftware/osrm-backend,deniskoronchik/osrm-backend,beemogmbh/osrm-backend,Project-OSRM/osrm-backend,bjtaylor1/osrm-backend,yuryleb/osrm-backend,bjtaylor1/osrm-backend,raymond0/osrm-backend,Project-OSRM/osrm-backend,oxidase/osrm-backend,beemogmbh/osrm-backend,hydrays/osrm-backend,neilbu/osrm-backend,frodrigo/osrm-backend,arnekaiser/osrm-backend,duizendnegen/osrm-backend,frodrigo/osrm-backend,oxidase/osrm-backend,arnekaiser/osrm-backend,hydrays/osrm-backend,arnekaiser/osrm-backend,bjtaylor1/osrm-backend,deniskoronchik/osrm-backend,oxidase/osrm-backend,beemogmbh/osrm-backend,hydrays/osrm-backend,frodrigo/osrm-backend,beemogmbh/osrm-backend,Project-OSRM/osrm-backend,deniskoronchik/osrm-backend,yuryleb/osrm-backend,KnockSoftware/osrm-backend,duizendnegen/osrm-backend,felixguendling/osrm-backend,duizendnegen/osrm-backend,neilbu/osrm-backend,raymond0/osrm-backend,oxidase/osrm-backend,arnekaiser/osrm-backend,deniskoronchik/osrm-backend,frodrigo/osrm-backend,neilbu/osrm-backend,felixguendling/osrm-backend,felixguendling/osrm-backend,neilbu/osrm-backend