== with long args is sub-optimal

[nrc]

e.g.,

    self.as_node().owner_doc().0 as *const structs::nsIDocument ==
        device
            .pres_context()
            .mDocument
            .raw::<structs::nsIDocument>()

Which Rustfmt formats as

    self.as_node().owner_doc().0 as *const structs::nsIDocument == device
        .pres_context()
        .mDocument
        .raw::<structs::nsIDocument>()

which hides the == a bit

[topecongiro]

Closing as this fixed on the current master:

    self.as_node().owner_doc().0 as *const structs::nsIDocument
        == device
            .pres_context()
            .mDocument
            .raw::<structs::nsIDocument>()