[PATCH] Revise linker plugin API to better preserve link order.

[PATCH] Revise linker plugin API to better preserve link order.

ld/ChangeLog:

2011-03-10  Dave Korn  <dave.korn.cygwin@gmail.com>

	* ldlang.h (lang_input_statement_type): Add new 'claim_archive' flag,
	wrapping both it and 'claim' flag in #ifdef ENABLE_PLUGINS.
	* ldmain.c (add_archive_element): Set it if the member is claimed.
	* ldlang.c (new_afile): Initialise claim_archive and claimed members.
	(find_replacements_insert_point): New helper function.
	(lang_process): After adding and opening replacement files passed
	from plugin, splice them into correct place in statement list and
	file chains to preserve critical link order.
	(lang_list_insert_after): New helper function.
	(lang_list_remove_tail): Likewise.