libcpp
	* include/symtab.h (HT_ALLOCED): Remove.
	(ht_purge): Declare.
	* symtab.c (DELETED): New define.
	(ht_lookup): Update comment.
	(ht_lookup_with_hash): Handle deleted entries.  Remove HT_ALLOCED
	code.  Use subobject allocator for strings, if it exists.
	(ht_expand): Handle deleted entries.
	(ht_forall): Likewise.
	(ht_purge): New function.
	(ht_dump_statistics): Print deletion statistics.
gcc
	* ggc-zone.c (lookup_page_table_if_allocated): New function.
	(zone_find_object_offset): Likewise.
	(gt_ggc_m_S): Likewise.
	(highest_bit): Likewise.
	* ggc-page.c (gt_ggc_m_S): New function.
	* stringpool.c (string_stack): Remove.
	(init_stringpool): Update.
	(ggc_alloc_string): Use ggc_alloc.
	(maybe_delete_ident): New function.
	(ggc_purge_stringpool): Likewise.
	(gt_ggc_m_S): Remove.
	* ggc-common.c (ggc_protect_identifiers): New global.
	(ggc_mark_roots): Call ggc_purge_stringpool.  Use
	ggc_protect_identifiers.
	* ggc.h (ggc_protect_identifiers): Declare.
	(gt_ggc_m_S): Update.
	(ggc_purge_stringpool): Declare.
	* toplev.c (compile_file): Set and reset ggc_protect_identifiers.
	* gengtype.c (write_types_process_field) <TYPE_STRING>: Remove
	special case.
	(write_root): Cast gt_ggc_m_S to gt_pointer_walker.
gcc/cp
	* mangle.c (save_partially_mangled_name): Remove.
	(restore_partially_mangled_name): Likewise.
	(write_encoding): Update.
	(write_unqualified_name): Likewise.
	(start_mangling): Always use name_obstack.  Remove 'ident_p'
	argument.
	(get_identifier_nocopy): Remove.
	(finish_mangling_internal): Rename from finish_mangling.
	(finish_mangling): New function.
	(finish_mangling_get_identifier): Likewise.
	(partially_mangled_name, partially_mangled_name_len): Remove.
	(mangle_decl_string): Change return type.  Update.
	(mangle_decl, mangle_type_string, mangle_special_for_type,
	mangle_ctor_vtbl_for_type, mangle_thunk, mangle_guard_variable,
	mangle_ref_init_variable): Update.

From-SVN: r135720