Unbreak the build when Boehm is enabled and remoting is disabled.
Fix some warnings caused by casts.
Silence a couple of unused variable warnings with G_GNUC_UNUSED.
Fix the tramp_names table when remoting is disabled.
Explicitly ignore some return values with a G_GNUC_UNUSED variable.
Only define get_local_interface_id () on Apple platforms.
Remove an unneeded inner `#ifndef DISABLE_COM`.
`#ifndef` some variables out to silence warnings in builds with COM/remoting disabled.