[RFA] Add new cmd line parameter "--pid" for attach.

[Elena Zannoni]

Andrew Cagney writes:
 > > About this, I have a question, what happens if you have a corefile
 > >> whose name starts with a digit? I tried it and I get an error:
 > 
 > 
 > I suspect the best thing to do is use a similar trick as recommended by 
 > some RM manuals given a file called ``-rf .'' i.e.  ./1234567
 > 
 > enjoy,
 > Andrew


"To remove a file called `-f' in the current directory, you could type
 either rm -- -f or rm ./-f "

I assume you mean 
gdb <symbolfile> ./2222core
not
gdb <symbolfile> -- 2222core


The first works fine.
I think we should mention this case in the docs.

Elena