cpplex.c (handle_newline, [...]): Update to do more stepping back.
* cpplex.c (handle_newline, skip_escaped_newlines,
get_effective_char, skip_block_comment, skip_line_comment,
parse_identifier_slow, parse_number, parse_string,
_cpp_lex_direct): Update to do more stepping back.
(trigraph_ok): Similarly. Rename trigraph_p.
(SAVE_STATE, RESTORE_STATE): Remove.
(BUFF_SIZE_UPPER_BOUND): Tweak. Add sanity check.
* cpplib.c (destringize): Rename destringize_and_run, and
call run_directive directly.
(_cpp_do__Pragma): Simplify.
From-SVN: r46373