[interop] Tracking issue to track support for immutable noncopyable borrows for C++ types in Swift

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We want to immutably borrow C++ types so that they can't be copied implicitly. A prime example of it is std::vector, which we want to pass into const std::vector & , or a call a const method on.

This issue is a tracking issue that tracks overall support for this feature in Swift. I will post updates here.

[hyp]

Let's not prioritize this for Swift 5.9

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Actually this appears to be still on track for 5.9.

[hyp]

This appears to work! I'm just going to add a test case for our expected patterns.

[hyp]

This works in 5.9 as well :)