Add rpath and soname support for FreeBSD/NetBSD/OpenBSD/DragonFlyBSD.

[ActuallyaDeviloper]

This extends the existing runpath and soname support to BSD.

Note that some BSD derivatives need the -z origin in addition to fix up $ORIGIN correctly. NetBSD and FreeBSD work without the flag, but it doesn't do any harm afaik so let's always set it.

runpathdirs_onRelativeDir_bsd is only the GCC tests, because the Clang flags are taken from GCC so a should single test should suffice.

AI disclosure: Claude Opus 5.5 helped navigate the code and craft the tests.

[ActuallyaDeviloper]

Ping.

I figure this is not getting as much attention because BSD is seen as a fringe use case and it's not easy to assess the validity of the flags from the outside. These flags have been in our premake since almost a decade, but with now cleaning up our build, using runpathdirs directly instead would be much nicer.

Is there something I can do to help it along?

[samsinsane]

My apologies, I remember looking at this and thought I'd reviewed it, but apparently not.

I figure this is not getting as much attention because BSD is seen as a fringe use case

Just wanted to clarify that this doesn't really have any impact for me, can't speak for the others but it usually just comes down to time for everyone.

These flags have been in our premake since almost a decade

Thanks for contributing it back, really appreciate it!