* stringpool.c: New file.
	* ggc-common.c (ggc_mark_string_ptr, ggc_add_string_root): Delete.
	(ggc_alloc_string): Now in stringpool.o.
	* ggc-page.c, ggc-simple.c: Do not define or allocate empty_string.
	* ggc.h: Delete prototype of ggc_add_string_root.  #define
	ggc_add_string_root and ggc_mark_string to nothing.  Prototype
	init_stringpool and stringpool_statistics.
	(ggc_alloc_string): Returns a const char *.
	* tree.c (hash_table, do_identifier_warnings): Delete.
	(init_obstacks): Don't initialize the identifier hash table.
	(get_identifier, maybe_get_identifier, start_identifier_warnings,
	set_identifier_size): Now in stringpool.c.
	* tree.h (struct tree_string): Constify pointer field.
	(approx_sqrt): Prototype.

	* Makefile.in (stringpool.o): Add rule, mention in OBJS.

	* toplev.c (approx_sqrt): New function.
	(compile_file): Call stringpool_statistics if mem_report is on.
	(main): Call init_stringpool.

	* builtins.c (c_strlen), c-decl.c (finish_decl), c-lex.c
	(process_directive), c-typeck.c (constructor_asmspec, struct
	initializer_stack, start_init), except.c (create_rethrow_ref),
	stmt.c (digit_strings), toplev.c (decode_f_option), tree.c
	(built_in_filename), varasm,c (in_named_name,
	assemble_static_space, struct constant_descriptor, struct
	deferred_string, struct pool_constant, force_const_mem),
	i386.c (pic_label_name, global_offset_table_name), rs6000.c
	(rs6000_emit_prologue, rs6000_emit_epilogue) : Constify a char *.

	* c-common.c (combine_strings): Combine strings in scratch
	buffer, then pass to build_string.
	* optabs.c (init_libfuncs), profile.c (init_edge_profiler,
	output_func_start_profiler), stmt.c (init_stmt), alpha.c
	(alpha_need_linkage), arm.c (arm_encode_call_attribute),
	i386.c (load_pic_register), ia64.c (ia64_encode_section_info),
	rs6000.c (rs6000_encode_section_info): Create string in
	scratch buffer, then pass to ggc_alloc_string.

	* stmt.c (expand_asm_operands): If we must adjust the
	constraint strings, do so by creating a new one, not by
	modifying the old one in place.  Constify some char *s.
	* config/pa/pa.c (hppa_encode_label): Drop unnecessary second
	argument.  Create string in scratch buffer, then pass to
	ggc_alloc_string.
	* config/pa/pa-protos.h: Update prototype.
	* config/pa/elf.h, config/pa/pa.h, config/pa/som.h:
	hppa_encode_label takes only one argument.

	* c-parse.in (if_prefix): Find the filename and line number at
	$-2 and $-1 respectively.
	* diagnostic.c (error_recursion): Add missing newline, use
	fputs, translate string.

cp:
	* lex.c (struct impl_files, internal_filename): Constify a char *.
java:
	* jcf-parse.c (get_constant), parse.y (do_merge_string_cste):
	Create string in scratch buffer, then pass to build_string.

From-SVN: r37514