cpp token_buffer not being NULL terminated causes fixproto bugs

[Jason Merrill]

Why aren't we NULL-terminating names anymore?  I specifically didn't change
that because of code that wants to use strcmp.  Using strncmp is wrong for
these cases, since the test will also match, say, "inlineasnotehu!!".

It might be appropriate to write a new macro which would test the length of
the token, do a strncmp and then test that the next character in the other
string is NULL.

Jason