Proposal to synthesize Equatable/Hashable for value types. (#706)
Proposal to synthesize Equatable/Hashable for value types. (#706)

* Proposal to synthesize Equatable/Hashable for value types.

* Updates based on the WIP implementation

* Update to match the proposal template

* Remove the _original type declaration_ requirement

* Fix typos

* Forbid synthesis in extensions (see SR-4920).

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