swift

b6cc118f - [cxx-interop] Explicit conversions between Swift and C++ spans

[cxx-interop] Explicit conversions between Swift and C++ spans A first step towards creating safe overloads for C++ APIs using span (rdar://139074571). Note that we need to mark span as owned because it the libc++ implementation was mistakenly recognized as owned and might now rely on span methods like `data` being renamed as `__dataUnsafe`. We will change it under a new interop version. But for the time being, we want consistent behavior across stdlib versions.