Simplify "run --target=XXX" command

[imphil]

What can we do to simplify the pattern to run a given target? Users don't want to type "fusesoc run --target=lint", but "fusesoc lint" just like they call "fusesoc build". Command line options to fusesoc always have been a bit tricky, so I'm not fully sure on the implications of making for example all targets available instead of "run", or having making the target a subcommand of run, e.g. "run lint".

[olofk]

Yes, it's a bit tricky but it can probably be improved. I don't want to introduce tool types again (e.g. build, sim, lint) as they caused a bit of a headache in capi1. So both the sim and build commands are considered deprecated and only run should be used. Maybe we can do some compromise. A couple of options

• Add core.target as shorthand syntax, e.g. fusesoc run my_core.lint. Want to be careful when we select the separator in that case
• Add -- switches, e.g. fusesoc run --lint my_core. Need to make sure they don't clash with other flags and can make options parsing a bit more complicated but should be doable