Auto merge of #90204 - cjgillot:owner-pull, r=michaelwoerister

Make lowering pull-based

~Based on https://github.com/rust-lang/rust/pull/90451~
Part of https://github.com/rust-lang/rust/pull/88186

The current lowering code visits all the item-likes in the AST in order, and lowers them one by one.
This PR changes it to index the AST and then proceed to lowering on-demand. This is closer to the logic of query-based lowering.