Build failure due to add-symbol-file-from-memory

[Joel Brobecker]

The following patch is causing a build failure on all platforms where
ELF is not used:

        * symfile.c (symbol_file_add_with_addrs_or_offsets): Take ABFD as
        argument instead of NAME.
        (symbol_file_add, reread_separate_symbols): Call symfile_bfd_open
        in call to symbol_file_add_with_addrs_or_offsets.
        (build_addr_info): New function, helper for ...
        (symbol_file_add_from_memory): New function.
        (add_symbol_file_from_memory_command): New function using that.
        (_initialize_symfile): Register it for add-symbol-file-from-memory.
        (pre_add_symbol_hook): Add const to argument type.
        * symfile.h (symbol_file_add_from_memory): Declare it.

That's because it makes a call to the following function:

        bfd_elf_bfd_from_remote_memory()

Which is not linked in when building for hppa-hpux for instance,
or ppc-aix, etc. Any easy way to fix the problem? Or should the
patch be backed out for now?

Thanks,
-- 
Joel