RFA: patch to fix gdb/1680

[Andrew Cagney]

[added keiths who knows a lot more about tcl/tk]

> drow> Does it work if you put a backslash in front of them instead?  That's
> drow> clearer to read, IMO.
> 
> On my machine (expect 5.41):
> 
>   "{...}"      ERROR: Process no longer exists
>   "\{...\}"    ERROR: Process no longer exists
>   "\\{...\\}"  Works fine

Try "{}" instead of {""}.  In these sorts of situtations that works a 
lot better.

Andrew