c/9928: [3.3/3.4 regression] ICE on duplicate enum declaration

[Eric Botcazou]

> This PR was introduced with Eric's patch that fixed another ICE (for
> c/7741): http://gcc.gnu.org/ml/gcc-patches/2003-02/msg00641.html

Thanks for spotting this! Please assign the PR to me.

-- 
Eric Botcazou