[patch] Fix PR fortran/27698 emit error when rejecting invalid name

[Paul Thomas]

Bernhard,

>
>PS: My machine is currently too busy, so this patchlet is not tested so
>far. I'd be glad if someone could take care of testing it. Feel free to
>apply if it's ok. Apologies for my lazyness and TIA
>
>  
>
Please test it; I think that it will break quite a lot of things but I 
could be wrong. 

gfc_match_name is often called as the first, or one of a series, of attempted matches.  A non-match does not necessarily mean an error, depending on the context.  I thought of doing the same but did not even try it for this reason.

Prove me wrong!

Thanks

Paul