`go run` compiles and runs a go program passing along the trailing args to the compiled program. Limiting `go run` to only complete *.go files means that if you are running a go file that takes a file path as a command line argument, you frustratingly cannot use tab completion.
It's now good enough to do so.
We don't allow grid-alignment:
```fish
complete -c foo -s b -l barnanana -a '(something)'
complete -c foo -s z -a '(something)'
```
becomes
```fish
complete -c foo -s b -l barnanana -a '(something)'
complete -c foo -s z -a '(something)'
```
It's just more trouble than it is worth.
The one part I'd change:
We align and/or'd parts of an if-condition with the in-block code:
```fish
if true
and false
dosomething
end
```
becomes
```fish
if true
and false
dosomething
end
```
but it's not used terribly much and if we ever fix it we can just
reindent.
As defined in the `go help packages`:
Many commands apply to a set of packages:
go action [packages]
Usually, [packages] is a list of import paths.
This patch introduces automatic lookup of said packages from GOPATH
using `go list`, and provides them as options go subcmds.
The tool subcommand had a "-f" flag to disallow file completions which is wrong: most of the tools there require a file/directory argument.
Since we're here, also limit "go tool compile" to only match Go source files.
