This allows us to: - Handle precise Places captured by a closure directly in MIR. Handling captures in MIR is easier since we can rely on/ tweak PlaceBuilder to generate `mir::Place`s that resemble how we store captures (`hir::Place`). - Allows us to handle `let _ = x` case when feature `capture_disjoint_fields` is enabled directly in MIR. This is required to be done in MIR since patterns are desugared in MIR.