Rollup merge of #57494 - dotdash:expand, r=nikomatsakis

Speed up item_bodies for large match statements involving regions

These changes don't change anything about the complexity of the algorithms, but use some easy shortcuts or modifications to cut down some overhead.

The first change, which incrementally removes the constraints from the set we're iterating over probably introduces some overhead for small to medium sized constraint sets, but it's not big enough for me to observe it in any project I tested against (not that many though).

Though most other crates probably won't improve much at all, because huge matches aren't that common, the changes seemed simple enough for me to make them.

Ref #55528

cc unicode-rs/unicode-normalization#29

r? @nikomatsakis

0 files changed, 0 insertions, 0 deletions