* dwarf2out.c (dwarf_file_data): New.
	(enum dw_val_class): Add dw_val_class_file.
	(struct dw_val_struct): Add val_file.
	(file_table): Change to a hash table.
	(file_table_emitted): Delete.
	(file_table_last_lookup_index): Delete.
	(emitcount): Delete.
	(last_emitted_file): New.
	(lookup_filename): Change prototype to return a struct dwarf_file_data.
	(init_file_table): Delete.
	(maybe_emit_file): Change prototype to take a struct dwarf_file_data.
	(AT_addr): Add comment.
	(add_AT_file): New.
	(AT_file): New.
	(get_AT_file): New.
	(print_die): Handle dw_val_class_file.
	(print_dwarf_line_table): Update for new file table structure.
	(attr_checksum): Do checksum a filename.
	(same_dw_val_p, same_attr_p): Do compare a filename.
	(size_of_die): Handle dw_val_class_file.
	(value_format): Likewise.
	(output_die): Likewise.  Also, call maybe_emit_file here.
	(struct file_info): Constify filenames.  Make file_idx a pointer
	to a struct dwarf_file_data.
	(struct dir_info): Constify directory names.  Remove 'used' field.
	(struct file_name_acquire_data): New.
	(file_name_acquire): New.
	(output_file_names): Modify to handle new file data structures.
	(add_src_coords_attributes): Use add_AT_file.
	(add_call_src_coords_attributes): Likewise.
	(dwarf2out_imported_module_or_decl): Likewise.
	(gen_subprogram_die): Modify for new file data structures.
	(gen_variable_die): Likewise.
	(file_table_eq): New.
	(file_table_hash): New.
	(file_table_last_lookup): New.
	(lookup_filename): Rewrite to handle new file data structures.
	(maybe_emit_file): Rewrite to handle new file data structures.
	(dwarf2out_source_line): Always call lookup_filename and
	maybe_emit_file.
	(dwarf2out_init): Create file_table here.
	(prune_unused_types_walk_attribs): Don't call maybe_emit_file here.
	(file_table_relative_p): New.
	(dwarf2out_finish): Change detection of relative filenames
	to work with new file data structures.  Move output_line_info call
	after debug_info output.

From-SVN: r116873