Use span snippet in all suggestions where possible

[estebank]

Suggestions should first attempt to use a span snippet instead of generated code (presumably a Ty) to avoid suggesting incorrect code:

warning: use of `unwrap_or` followed by a function call
   --> policy.rs:481:46
    |
481 |         .iter().map(|a| a.into()).collect()).unwrap_or(vec![]),
    |                                              ^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| < [ _ ] > :: into_vec ( box [ $ ( $ x ) , * ] ))`
    |
    = note: #[warn(or_fun_call)] on by default
    = help: for further information visit https://rust-lang-nursery.github.io/rust-clippy/v0.0.212/index.html#or_fun_call

[oli-obk]

Uh... that's what we're doing. But the span points to the expanded tokens. We need to figure out the unexpanded span for most of these things

[estebank]

This could be sidestepped by pointing the span only to unwrap_or and suggest unwrap_or_else, instead of the entire call. To do so might require doing some span wrangling though :-/