* c-lex.c (read_escape, read_ucs): Delete.
(lex_string): Use cpp_parse_escape.
* cpplex.c (read_ucs): Rename maybe_read_ucs. Do nothing
if not C++ or not C99. Warn if traditional.
(parse_escape): Rename cpp_parse_escape. Make the bitmask
unsigned. Warn for out-of-range escape sequences here.
Update to use maybe_read_ucs.
(cpp_interpret_charconst): Don't warn here.
* cpplib.h (cpp_parse_escape): New exported function.