Resolve upstream unused variables so we can remove the -Wno-unused

Resolve upstream unused variables so we can remove the -Wno-unused
compile option.  In most case the variables are only unused when
debugging is disabled (ASSERT) however they do waste stack if that
case if the compiler doesn't optimize it out (it should).  But more
importantly disabling this warning prevent us from noticing legit
unused variables accidentally left in other place of the code.