C frontend cpplib integration patch

[Gavin Romig-Koch]

This is OK, thanks.

                                 -gavin...


 > Fri Jul 23 17:15:10 1999  Jason Merrill  <jason@yorick.cygnus.com>
 > 
 > 	* c-lex.c: Sync with C++ frontend.
 > 	(linemode): New variable.
 > 	(parse_float): imag, conversion_errno, and type are output only.
 > 	(yylex): Adjust.  Move initial '.' case into main switch.
 > 	Use linemode.
 > 	(handle_generic_pragma): Just deal with tokens.
 > 	(readescape): Use ISXDIGIT and ISGRAPH.
 > 	* c-parse.in: Add END_OF_LINE token.
 > 
 > 	* c-lex.c (lang_init): Generalize.
 > 	(nextchar): Remove.  Replace uses with UNGETC.
 > 	(skip_white_space): Handle linemode here.  Optimize for cpplib.
 > 	(skip_white_space_on_line): Remove.
 > 	(extend_token_buffer_to): New fn.
 > 	(extend_token_buffer): Use it.
 > 	(read_line_number, check_newline): Just deal with tokens.
 > 	(token_getch, token_put_back): New fns.
 > 	(yylex): Use them.  More cpplib optimizations.  Simplify.
 > 
 > Fri Jul 23 17:15:10 1999  Michael Tiemann  <tiemann@holodeck.cygnus.com>
 > 			  Jason Merrill  <jason@yorick.cygnus.com>
 > 
 > 	* c-lex.c (init_parse): Set cpp_token to CPP_DIRECTIVE.
 > 	(consume_string): Make this smart about USE_CPPLIB.
 > 	(check_newline): Rewrite to be intelligent about USE_CPPLIB.
 > 	(yylex): Rewrite to be intelligent about USE_CPPLIB.
 > 	Also, clean up cases where we redundantly set token_buffer[0].
 > 	(read_line_number): New fn.
 > 	(ignore_escape_flag): New variable.