[Import as member] Amendments for subscripts and protocols.
[Import as member] Amendments for subscripts and protocols.

Explicitly call out subscripts, which will need a new special named
value 'newValue'. Permit importing onto protocols, so long as the
member is an instance member, and this will be imported onto an
extension of the named protocol.

Nirma/swift-evolution,hartbit/swift-evolution,airspeedswift/swift-evolution,DougGregor/swift-evolution,apple/swift-evolution,DevAndArtist/swift-evolution,apple/swift-evolution,bolshedvorsky/swift-evolution,johnno1962a/swift-evolution,jtbandes/swift-evolution,johnno1962a/swift-evolution,aciidb0mb3r/swift-evolution,abertelrud/swift-evolution,natecook1000/swift-evolution,abertelrud/swift-evolution,ddunbar/swift-evolution,jtbandes/swift-evolution,rballard/swift-evolution,anandabits/swift-evolution,allevato/swift-evolution,allevato/swift-evolution,airspeedswift/swift-evolution,ddunbar/swift-evolution,rballard/swift-evolution,DevAndArtist/swift-evolution,aciidb0mb3r/swift-evolution,hartbit/swift-evolution,jckarter/swift-evolution,singcodes/swift-evolution,DougGregor/swift-evolution,jckarter/swift-evolution,Nirma/swift-evolution,anandabits/swift-evolution,bolshedvorsky/swift-evolution,singcodes/swift-evolution,natecook1000/swift-evolution