[Bug c/70186] RFE: better handling of misspelled attributes

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70186

--- Comment #2 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Candidate patch posted here:
  https://gcc.gnu.org/ml/gcc-patches/2016-12/msg01610.html