Now that the link graph is acyclic, it should be safe and even desirable to remove the -Wl,--start-group and --Wl,--end-group arguments in the Linux and BSD builds. It should actually be OK to remove the entire LINK_LIBGROUP_START and LINK_LIBGROUP_END concepts from libdeps as well. It's a minor code simplification, and may modestly speed up static link times on systems with older linkers.

Unfortunately, the "whole archive" requirement remains.