cppexp.c, [...]: Do not use 'legal' or 'illegal' in error messages and comments.
* cppexp.c, cppinit.c, cpplex.c, cpplib.c, cppmacro.c,
cppspec.c: Do not use 'legal' or 'illegal' in error messages
and comments.
* cppmain.c (cb_define, cb_undef): Don't generate any output
if not done_initializing.
* cpplex.c (maybe_paste_with_next): When the token after a ##
is an omitted rest argument, only delete the token before it
if that token is a comma. Do not warn about bogus token
pastes for , ## rest_arg.