* c-family/c-common.c (handle_alias_ifunc_attribute): Do not set
	DECL_EXTERNAL for weakref variables.
	* c-family/c-pragma.c (handle_pragma_weak): Make sure aliases
	are not declared as external.
	* cgraph.c (cgraph_create_function_alias): Set weakref flag.
	* cgraph.h (symtab_node_base): Add weakref flag.
	* cgraphunit.c (cgraph_reset_node): Clear weakref flag.
	(handle_alias_pairs): Set weakref flag, do not set DECL_EXTERNAL.
	(output_weakrefs): Use weakref flag.
	* fold-const.c (simple_operand_p): Handle WEAK.
	* gimple-fold.c (can_refer_decl_in_current_unit_p): Drop weakref.
	* ipa.c (varpool_externally_visible_p): Drop weakref.
	(function_and_variable_visibility): Update comment; fix weakref
	sanity checks; do not clear DECL_WEAK on them.
	* lto-cgraph.c (lto_output_node): update.
	(lto_output_varpool_node): Update.
	(input_overwrite_node): Update.
	(input_node): Update.
	(input_varpool_node): Update.
	* lto-symtab.c (lto_symtab_symbol_p): Do not special case weakrefs.
	(lto_symtab_merge_symbols): Add sanity check.
	(lto_symtab_prevailing_decl): Do not special case weakrefs.
	* passes.c (rest_of_decl_compilation): Set static flag, too.
	* symtab.c (dump_symtab_base): Dump weakref.
	(verify_symtab_base): Sanity check weakrefs.
	(symtab_make_decl_local): Remove duplicated code.
	(symtab_alias_ultimate_target): Simplify.
	* varpool.c (varpool_create_variable_alias): Set weakref flag.

	* lto-partition.c (get_symbol_class): Simplify weakref handling.
	(add_symbol_to_partition_1): Likewise.
	(contained_in_symbol): Likewise.
	(lto_balanced_map): Likewise.
	(rename_statics): Drop weakref.

From-SVN: r199971