The "next available source_location" is now managed internally by
	line-maps.c rather than by clients.
	* line-map.h (struct line_map):  New field column_bits.
	<from_line>:  Rename field to start_location.
	(struct line_maps):  New fields highest_location and max_column_hint.
	(linemap_check_files_exited):  New declaration.
	(linemap_line_start):  New declaration.
	(linemap_add):  Remove from_line parameter; use highest_location field.
	(SOURCE_LINE, LAST_SOURCE_LINE):  Modify to use column_bits.
	(SOURCE_COLUMN, LAST_SOURCE_LINE_LOCATION):  New macros.
	(CURRENT_LINE_MAP):  Remove macro.
	(linemap_position_for_column):  New inline function.
	* line-map.c (linemap_init):  Clear new fields.
	(linemap_check_files_exited):  New function, extracted from ...
	(linemap_free):  Use linemap_check_files_exited.
	(linemap_add):  Remove from_line parameter.  Various updates.
	(linemap_line_start):  New function.
	(linemap_lookeup):  Update for new field names.
	* cpphash.h (struct cpp_reader) <map>:  Field removed.  Because
	linemap_position_for_column may unpredictably change the current map,
	it is cleaner and simpler for us to not cache it in cpp_reader.
	(struct cpp_buffer):  New sysp field.
	Changed warned_cplusplus_comments and from_stage3 to bitfields.
	* cppinit.c (cpp_read_min_file):  pfile->map no longer exists.
	* cpplib.c (do_line, do_linemarker, _cpp_do_file_change):  Get
	current map using linemap_lookup.
	(do_linemarker):  Also set buffer's sysp field.
	(destringize_and_run):  No longer need to decrement current line.
	* cppfiles.c (_cpp_stack_file):  Set sysp from and in buffer.
	(search_path_head, open_file_failed):  Use buffer's sysp.
	(cpp_make_system_header):  Get current map using linemap_lookup.
	Also set buffer's sysp flag.
	* cppmacro.c (_cpp_builtin_macro_text):  Likewise use linemap_lookup.
	* cpphash.h (CPP_INCREMENT_LINE):  New macro.
	(struct cpp_buffer):  Moved fields saved_cur, saved_rlimit to ...
	(struct cpp_reader):  ... and adding saved_line_base field.
	* cpptrad.c (_cpp_overlay_buffer, _cpp_remove_overlay):
	Update accordingly.  Don't adjust line.
	(_cpp_scan_out_logical_line):  Use CPP_INCREMENT_LINE.
	* cpphash.c (CPP_IN_SYSTEM_HEADER):  Replaced macro by ...
	(cpp_in_system_header):  ... new inline function, using buffer's sysp.
	* cpperror.c (_cpp_begin_message):  Update to use cpp_in_system_header.
	* cpplex.c (_cpp_lex_direct):  Likewise.
	* cppmacro.c (_cpp_builtin_macro_text):  Likewise.
	* cppmacro.c (_cpp_create_definition):  Use buffer's sysp field.
	* cpplib.h (struct cpp_token):  Rename line field to src_loc.
	Remove col field as it is now subsumed by src_loc.
	* cpperror.c:  Update various field, parameter, and macro names.
	(print_location):  If col==0, try SOURCE_COLUMN of line.
	(cpp_error):  Use cur_token's src_loc field, rather than line+col.
	* cpplib.c (do_diagnostic):  Token's src_loc fields replaces line+col.
	* cpplex.c (_cpp_process_line_notes, _cpp_lex_direct,
	_cpp_skip_block_comment):  Use CPP_INCREMENT_LINE.
	(_cpp_temp_token):  Replace cpp_token's line+col fields by src_loc.
	(_cpp_get_fresh_line):  Don't need to adjust line for missing newline.
	(_cpp_lex_direct):  Use linemap_position_for_column.
	* c-ppoutput.c (maybe_print_line, print_line):  Don't take map
	parameter.  Instead get it from the line_table global.  Adjust callers.
	(print):  Remove map field.  Replace line field to src_line.
	(init_pp_output, account_for_newlines, maybe_print_line):  Adjust.
	(cb_line_change):  Use SOURCE_COLUMN.  Minor optimizations.
	(pp_file_change):  Use MAIN_FILE_P since we cannot checked print.map.
	Use LAST_SOURCE_LINE_LOCATION to "catch up" after #include.
	* cpptrad.c (copy_comment):  Rename variable.
	* c-lex.c (map):  Remove static variable, for same reason we removed
	cpp_reader's map field.
	(cb_line_change, cb_def_pragma, cb_define, cb_undef):  Hence we need
	to call linemap_lookup.
	(cb_line_change):  Token's line field replaced by src_loc.
	(fe_file_change):  Use MAINFILE_P and LAST_SOURCE_LINE macros.
	Don't save new_map.

	* cpphash.h, cpperror.c, cpplib.h:  Some renames of fileline to
	source_location.

From-SVN: r77663