[stdlib] Add "copy init" methods for bridged types
[stdlib] Add "copy init" methods for bridged types

Fixes <rdar://problem/19755780>

Swift SVN r25187

apple/swift-corelibs-foundation,apple/swift-corelibs-foundation,apple/swift-corelibs-foundation,apple/swift-corelibs-foundation,apple/swift-corelibs-foundation