spans in macros have regressed

[Xanewok]

Originally created by @nrc (rust-dev-tools/rls-analysis#75):

e.g.,

    let world = "world";
    println!("Hello, {}!", world);

The ref for world on the second line used to point to the correct def on the first line, but now points at itself.

[Xanewok]

Originally replied by @nrc (rust-dev-tools/rls-analysis#75 (comment)):

cc rust-dev-tools/rls-analysis#74 (which was magically fixed, but perhaps just because we're doing less, so might appear when this is fixed).

[Xanewok]

Fixed now, so closing.