Release 2020-06-17 toolchain for macOS. (#488)
Release 2020-06-17 toolchain for macOS. (#488)

https://github.com/apple/swift/commit/f2b25f73556ec379d9482cd9ce93f80badbf658b
https://github.com/tensorflow/swift-apis/commit/2500de10cfa2ecc9a8427dfb0a0d789aa9cdb83e
tensorflow/swift,tensorflow/swift