[patch ld]: Improve speed for import-table resolving for aliases

[nick clifton]

Hi Kai,

> 2012-03-09  Kai Tietz<ktietz@redhat.com>
> 	Pascal Obry<pascal@obry.net>
>
> 	* pe-dll.c (found_sym): New static variable.
> 	(undef_count): Likewise.
> 	(key_value): New structure.
> 	(undef_sort_cmp): Compare routine for qsort/bsearch.
> 	(pe_find_cdecl_alias_match): Add new argument.
> 	(pe_undef_alias_cdecl_match): Removed.
> 	(pe_undef_count): New helper routine.
> 	(pe_create_undef_table): Likewise.
> 	(pe_process_import_defs): Use pe_create_undef_table and
> 	new pe_undef_alias_cdecl_match function.
>
> Patch tested for i686-w64-mingw32, x86_64-w32-mingw32, and
> i686-pc-cygwin.  Ok for apply?

Approved - please apply.

Cheers
   Nick