swift

27dfbd19 - [AutoDiff] Move stdlib sources to stdlib/public/core/Differentiation. (#28089)

[AutoDiff] Move stdlib sources to stdlib/public/core/Differentiation. (#28089) Move differentiable-programming-related stdlib sources to `stdlib/public/core/Differentiation`. Related master branch PR: https://github.com/apple/swift/pull/27511. master branch will have a `_Differentiation` support library containing the `Differentiable` protocol and related APIs. On tensorflow branch, the Swift source files in `stdlib/public/core/Differentiation` will be directly built as part of swiftCore for simplicity. Swift for TensorFlow users can continue to use the `Differentiable` protocol and related APIs without adding `import _Differentiation`. - Create empty `_Differentiation` module on tensorflow branch to avoid `#if canImport(_Differentiation)` checks in upstreamed AutoDiff tests. - Rename `protocol _Differentiable` back to `protocol Differentiable`. - Expose SR-11723. Workaround applied to fix validation-test/ParseableInterface/verify_stdlib.swift.