elflink.c/elf_add_symbol_hook symbol skipping

[Douglas B Rupp <rupp at gnat dot com>]

VMS libraries have a feature called selective_search. For an object so 
flagged in a library, and then loaded from the archive in a subsequent 
linking operation: only those symbols that satisfy undefs are added.

I've been trying to implement this with elf_add_symbol_hook by returning 
a null name for a symbol that should be skipped, e.g. in accordance with 
the elflink.c/elf_link_add_object_symbols() comment:

          /* The hook function sets the name to NULL if this symbol
             should be skipped for some reason.  */
          if (name == NULL)
            continue;

Setting the name to null wrecks tremendous havoc later in the link. I'm 
looking for some ideas on how to make this work.

--Doug