[15/21] Avoid writing duplicate XCOFF symbols

[Nick Clifton]

Hi Richard,

> include/coff/
> 	* xcoff.h (XCOFF_ALLOCATED): New flag.
> 
> bfd/
> 	* xcofflink.c (xcoff_mark): When walking the relocations,
> 	only mark the target symbol or the target section, not both.
> 	(xcoff_final_definition_p): New function.
> 	(xcoff_keep_symbol_p): Use it to check whether an external XCOFF
> 	symbol is a valid definition of the associated output symbol.
> 	Use XCOFF_ALLOCATED to stop the same hash table entry having
> 	two output symbols.
> 	(bfd_xcoff_size_dynamic_sections): Set XCOFF_ALLOCATED when
> 	keeping a symbol.
> 	(xcoff_link_input_bfd): Use xcoff_final_definition_p.
> 
> ld/testsuite/
> 	* ld-powerpc/aix-no-dup-syms-1a.s, ld-powerpc/aix-no-dup-syms-1b.s,
> 	ld-powerpc/aix-no-dup-syms-1.ex, ld-powerpc/aix-no-dup-syms-1.im,
> 	ld-powerpc/aix-no-dup-syms-1-dso.dnd,
> 	ld-powerpc/aix-no-dup-syms-1-dso.drd,
> 	ld-powerpc/aix-no-dup-syms-1-dso.nd,
> 	ld-powerpc/aix-no-dup-syms-1-dso.rd,
> 	ld-powerpc/aix-no-dup-syms-1-rel.nd,
> 	ld-powerpc/aix-no-dup-syms-1-rel.rd: New tests.
> 	* ld-powerpc/aix52.exp: Run them.


Approved - please apply.

Cheers
   Nick