Dead driver options

Several options are declared in the linker driver TableGen files but never referenced anywhere in the linker source. Passing them on the command line is silently accepted but does nothing. If any of these are intentionally ignored for compatibility reasons, they should go in grp_compatorignoredopts.

This is misleading because the flags appear in --help output, giving the appearance that they are functional.

Affected options:

This was checked by grep-ing each option's td identifier against eld source.

Options supported by GNU ld:

--allow-shlib-undefined
--no-allow-shlib-undefined
--add-needed
--no-add-needed
--copy-dt-needed-entries
--no-copy-dt-needed-entries
--fix-cortex-a8
--no-fix-cortex-a8
--library-path[=<path>]
--Ttext-segment=<address>
--rpath-link[=<path>]
--hash-size=<size>
-g                            # gold 

We might be making misleading GNU compatibility claims with these options.

ELD-specific:

--map-section=<section>
--align-segments            
--use-shlib-undefines