[racket] Can raco exe assign a name other than "racket"?

At Mon, 28 Mar 2011 07:28:54 -0600, Matthew Flatt wrote:
> To change the name shown by `ps', it looks like Racket could call
> prctl() with PR_SET_NAME --- at least for Linux (2.6.9 and up). I'll
> look into that more.

I've pushed that change. Racket sets the process name to match the -N
argument if supplied, otherwise it sets the name to match argv[0].

The latter makes `raco exe'-produced executables have the expected
name, and the former makes `drracket' start a process with the name
`drracket' (instead of `gracket').