* doc/tm.texi (ASM_WEAKEN_DECL): Document.
	(ASM_WEAKEN_LABEL): Mention ASM_WEAKEN_DECL.
	(SUPPORTS_WEAK): Likewise.
	* output.h (add_weak): Add tree param.
	* varasm.c (add_weak): Likewise.  Save decl.
	(struct weak_syms): Add decl field.
	(mark_weak_decls): New function.
	(init_varasm_once): ggc_add_root mark_weak_decls.
	(assemble_start_function): Use ASM_WEAKEN_DECL.
	(assemble_variable): Likewise.
	(assemble_alias): Likewise.
	(declare_weak): Pass decl to add_weak.
	(weak_finish): Use ASM_WEAKEN_DECL. Try to find decl.
	(remove_from_pending_weak_list): Declare and define for
	ASM_WEAKEN_DECL.
	* c-pragma.c (handle_pragma_weak): Adjust add_weak call.
	* c-pragma.h (HANDLE_PRAGMA_WEAK): Define if ASM_WEAKEN_DECL too.
	* defaults.h (SUPPORTS_WEAK): Likewise.
	* config/rs6000/linux64.h (ASM_DECLARE_FUNCTION_NAME): Don't emit
	.weak for code sym.  Do emit .size for descriptor sym.
	(ASM_DECLARE_FUNCTION_SIZE): Define.
	* config/rs6000/rs6000.h (ASM_WEAKEN_DECL): Define.
	(ASM_OUTPUT_DEF_FROM_DECLS): Don't emit .weak here.  Don't output
	.lglobl unless TARGET_XCOFF.  Formatting fixes.
	* config/rs6000/xcoff.h (ASM_DECLARE_FUNCTION_NAME): Don't emit
	.weak for code sym.
	(HANDLE_PRAGMA_WEAK): Remove.
	(ASM_WEAKEN_LABEL): Remove.
	* config/rs6000/aix.h (HANDLE_SYSV_PRAGMA): Define.

Co-Authored-By: David Edelsohn <edelsohn@gnu.org>

From-SVN: r50181