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Issue Description:

I rely upon a closure for type erasure at a different layer.

When I set a breakpoint and inspect the variable at each level, it is valid at the top of the call stack, as it goes down into closures the memory gets disassociated and I can no longer inspect the value.

In Swift 5.x, the closure and method dispatch do not crash, but the evaluation is incorrect.

If I use a typealias, then everything works as expected.

I have a cleanly compiling project with clean unit tests.

When I apply the attached patch, I would expect the same to be true.

What happens today is everything compiles, but some unit tests fail.

https://github.com/crewos/fetchrequests

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This has not worked in most versions of Swift.

In at least one version it had worked – I think the swift 4 betas.

In prior versions of Swift the evaluation would crash.

In Swift 5.x it does not crash, but the pointer addresses are invalid.

In the past, the RawData type was a [String: Any], which had the same problems.