Function difft::diff::sliders::fix_all_nested_sliders

fn fix_all_nested_sliders<'a>(
    language: Language,
    nodes: &[&'a Syntax<'a>],
    change_map: &mut ChangeMap<'a>
)

Correct sliders in middle insertions.

Consider the code:

// Before
old1(old2);
// After
old1(new1(old2));

Tree diffing has two possible solution here. Either we’ve added new1(...) or we’ve added (new1...). Both are valid.

For C-like languages, the first case matches human intuition much better. Fix the slider to make the inner delimiter novel.