had not be implemented. It would cause an "adress space leak" and, if
the same object would opened multiple time, unwanted relocations.
Re: Comment from Chris:
"The a.out ld.so has some problems with dlclose. It doesn't properly
unmap objects which are dlclosed. That's a known problem (though a
serious one for programs which dlopen then dlclose lots of objects,
because it causes address space exhaustion), but it has a
previously-unknown side-effect.
If a single object is dlopened, then dlclosed, then dlopened _again_,
the relocations will be processed again. That causes obvious
problems."