Adjust style-servo patch

[Mark-Simulacrum]

This adjusts the style-servo println patch to be in a non-templated file.
Previously, the properties file change would cause the build script to rerun.

[Mark-Simulacrum]

We'll likely want to re-collect stable (i.e., dashboard) benchmarks to account for this adjustment to style-servo, but that can be done later when our queue isn't suffering quite as much :)

[Mark-Simulacrum]

I suspect that the old patch was technically still fine -- it caused a single-line change to the output of the template. But editing a 141,865 line file means that our current codegen unit partioning strategy is going to recompile a lot more as a result.

@nnethercote I'm going to let you weigh in before we merge this (or not). IMO, this PR brings the patch more inline with what we expect from the println patches -- small edits to small CGUs. Alternatively we can call this a bug in rustc that a small edit to a large module represents a lot of recompilation (maybe related to the generated nature of the file, i.e., that it's all included via a include! macro?).

cc @oli-obk @wesleywiser @pnkfelix who I believe are currently working on incremental / CGU partioning, but feel free to cc others if I've categorized incorrectly.

[Mark-Simulacrum]

For reference, here is the generated file: https://gist.github.com/Mark-Simulacrum/9fe9b6fde89c4598c4ae0c13f45bad12

[nnethercote]

I don't have a strong preference here. Changing the println location seems reasonable.

[Mark-Simulacrum]

Okay, I'll go ahead and merge this then. It should be a slight increase in the instructions stat for the style-servo incremental tests but not as significant as what we saw the drop as.

I'll also work on recollecting stable builds.