Preserve narrowing in unreachable code #20710
Open
+115
−165
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In the future, it would be nice to have an option to continue to check unreachable code. See #18707 from A5rocks. This PR lays some semantics preserving groundwork for that.
This is effectively a subset of #18707 , but I go just a little bit further and change the type of TypeMap to exclude None
Btw A5rocks if you are willing to rebase your PR, that would be great. I think
--check-unreachablewill be a very useful feature.Co-authored-by: A5rocks