#5962 Avoid using Skyline_pair::insert.

[Han-Wen Nienhuys]

Skyline::insert(Box) creates a skyline and merges it. In this case,
the boxes are non-overlapping, so it is trivial to create a skyline
out of them.

Remove Skyline::insert(). Using it repeatedly leads to a quadratic
complexity, so it's best avoided.

Timing benchmarks are neutral

https://codereview.appspot.com/554000043

[Anonymous]

Passes make, make check and a full make doc.

[Anonymous]

Patch on countdown for May 6th

[Anonymous]

Patch counted down - please push

[Jonas Hahnfeld]

commit b872b327c471a9538d93fba21ff0385709aae2c2
Author:     Han-Wen Nienhuys <hanwen@lilypond.org>
AuthorDate: Sun May 3 20:31:10 2020 +0200
Commit:     Han-Wen Nienhuys <hanwen@lilypond.org>
CommitDate: Fri May 8 09:14:55 2020 +0200

    Avoid using Skyline_pair::insert.

    Skyline::insert(Box) creates a skyline and merges it. In this case,
    the boxes are non-overlapping, so it is trivial to create a skyline
    out of them.

    Remove Skyline::insert(). Using it repeatedly leads to a quadratic
    complexity, so it's best avoided.

    Timing benchmarks are neutral