Rollup merge of #114196 - compiler-errors:bubble-pls, r=lcnr

Bubble up nested goals from equation in `predicates_for_object_candidate`

This used to be needed for rust-lang/rust#114036 (comment), but since it's no longer, I'm opening this as a separate PR. This also fixes one ICEing UI test: (`tests/ui/unboxed-closures/issue-53448.rs`)

r? `@lcnr`