Uses visual style for long closure arguments

[joshtriplett]

rustfmt seems to use visual style rather than block style when reformatting long closure argument lists:

    let write_status = |status: &mut Vec<ansi_term::ANSIString>,
                        diff: &Diff,
                        heading: &str,
                        color: &Style,
                        show_hints: bool,
                        hints: &[&str]|
     -> Result<bool> {

One possible block-style alternative rustfmt could use:

    let write_status = |
        status: &mut Vec<ansi_term::ANSIString>,
        diff: &Diff,
        heading: &str,
        color: &Style,
        show_hints: bool,
        hints: &[&str]
    | -> Result<bool> {

[calebcartwright]

Yeah even though block indent style is the default for everything else, closures seem to be the exception that are always formatted with visual style.

I'll open a PR today with an update (version gated) to leverage the indent_style config option when formating the closure to offer consistency with function declarations.

[topecongiro]

cc rust-lang/style-team#138.

[calebcartwright]

Reopening as this was closed as part of a change applied to a now-defunct and abandoned branch