1Some tests targeted at how we deduce the types of closure arguments. 2This process is a result of some heuristics aimed at combining the 3*expected type* we have with the *actual types* that we get from 4inputs. This investigation was kicked off by #38714, which revealed 5some pretty deep flaws in the ad-hoc way that we were doing things 6before. 7 8See also `src/test/ui/closure-expected-type`. 9