Remove references to VectorProtocol from AD tests.

test/AutoDiff/derived_differentiable.swift

@@ -44,7 +44,7 @@ struct TestNoDerivative : EuclideanDifferentiable {
 // CHECK-AST:         var w: Float
 // CHECK-AST:         @noDerivative internal var technicallyDifferentiable: Float
 // CHECK-AST:         internal init(w: Float, technicallyDifferentiable: Float)
-// CHECK-AST:         internal struct TangentVector : _Differentiable, AdditiveArithmetic, ElementaryFunctions, VectorProtocol
+// CHECK-AST:         internal struct TangentVector : _Differentiable, AdditiveArithmetic, ElementaryFunctions
 // CHECK-AST:           internal typealias TangentVector = TestNoDerivative.TangentVector
 // CHECK-AST:         internal var differentiableVectorView: TestNoDerivative.TangentVector { get }
 

test/AutoDiff/differentiable_attr_type_checking.swift

@@ -271,7 +271,7 @@ extension JVPStruct {
   }
 }
 
-extension JVPStruct : VectorProtocol {
+extension JVPStruct : AdditiveArithmetic {
   static var zero: JVPStruct { fatalError("unimplemented") }
   static func + (lhs: JVPStruct, rhs: JVPStruct) -> JVPStruct {
     fatalError("unimplemented")
@@ -419,7 +419,7 @@ extension VJPStruct {
   }
 }
 
-extension VJPStruct : VectorProtocol {
+extension VJPStruct : AdditiveArithmetic {
   static var zero: VJPStruct { fatalError("unimplemented") }
   static func + (lhs: VJPStruct, rhs: VJPStruct) -> VJPStruct {
     fatalError("unimplemented")

test/AutoDiff/differentiating_attr_type_checking.swift

@@ -256,15 +256,15 @@ func bar<T>(_ x: T) -> T {
   return x
 }
 @differentiating(bar)
-func vjpBar<T : Differentiable & VectorProtocol>(_ x: T) -> (value: T, pullback: (T.TangentVector) -> T.TangentVector) {
+func vjpBar<T : Differentiable>(_ x: T) -> (value: T, pullback: (T.TangentVector) -> T.TangentVector) {
   return (x, { $0 })
 }
 
 func baz<T, U>(_ x: T, _ y: U) -> T {
   return x
 }
 @differentiating(baz)
-func vjpBaz<T : Differentiable & VectorProtocol, U : Differentiable>(_ x: T, _ y: U)
+func vjpBaz<T : Differentiable, U : Differentiable>(_ x: T, _ y: U)
     -> (value: T, pullback: (T) -> (T, U))
   where T == T.TangentVector, U == U.TangentVector
 {

test/AutoDiff/differentiation_transform_diagnostics.swift

@@ -19,9 +19,9 @@ _ = gradient(at: 0, in: one_to_one_0) // okay!
 struct S {
   var p: Float
 }
-extension S : Differentiable, VectorProtocol {
+extension S : Differentiable, AdditiveArithmetic {
   // Test custom `TangentVector` type with non-matching stored property name.
-  struct TangentVector: Differentiable, VectorProtocol {
+  struct TangentVector: Differentiable, AdditiveArithmetic {
     var dp: Float
   }
   typealias AllDifferentiableVariables = S

test/AutoDiff/e2e_differentiable_property.swift

@@ -8,7 +8,7 @@ import StdlibUnittest
 
 var E2EDifferentiablePropertyTests = TestSuite("E2EDifferentiableProperty")
 
-struct TangentSpace : VectorProtocol {
+struct TangentSpace : AdditiveArithmetic {
   let x, y: Float
 }
 
@@ -81,7 +81,7 @@ E2EDifferentiablePropertyTests.test("generic stored property") {
   expectEqual(expectedGrad, actualGrad)
 }
 
-struct ProductSpaceSelfTangent : VectorProtocol {
+struct ProductSpaceSelfTangent : AdditiveArithmetic {
   let x, y: Float
 }
 
@@ -97,7 +97,7 @@ E2EDifferentiablePropertyTests.test("fieldwise product space, self tangent") {
   expectEqual(expectedGrad, actualGrad)
 }
 
-struct ProductSpaceOtherTangentTangentSpace : VectorProtocol {
+struct ProductSpaceOtherTangentTangentSpace : AdditiveArithmetic {
   let x, y: Float
 }
 

test/AutoDiff/forward_mode_runtime.swift

@@ -356,7 +356,7 @@ ForwardModeTests.test("TupleNonDifferentiableElements") {
 //===----------------------------------------------------------------------===//
 
 struct Tensor<Scalar : FloatingPoint & Differentiable> 
-  : VectorProtocol, Differentiable {
+  : AdditiveArithmetic, Differentiable {
   // NOTE: `value` must have type with known size (e.g. `Float`, not `Scalar`)
   // until differentiation has indirect passing support.
   var value: Float
@@ -799,7 +799,7 @@ protocol Prot : Differentiable {
   func foo(x: Float) -> Float
 }
 ForwardModeTests.test("Simple Protocol") {
-  struct Linear: Prot, VectorProtocol {
+  struct Linear: Prot, AdditiveArithmetic {
     typealias TangentVector = Linear
 
     let m: Float
@@ -832,7 +832,7 @@ extension DiffReq where TangentVector : AdditiveArithmetic {
   }
 }
 
-struct Quadratic : DiffReq, VectorProtocol {
+struct Quadratic : DiffReq, AdditiveArithmetic {
   typealias TangentVector = Quadratic
 
   @differentiable

test/AutoDiff/generics.swift

@@ -16,7 +16,7 @@ _ = gradient(at: Float(1), in: { x in identity(x) })
 // CHECK-SIL-NEXT: [[EMIT_ZERO_INDIRECT:%.*]] = apply [[ZERO_WITNESS]]<τ_0_0.TangentVector>([[ORIG_COTAN]], [[ORIG_COTAN_METATYPE]])
 // CHECK-SIL: }
 
-struct Tensor<Scalar : FloatingPoint & Differentiable> : VectorProtocol, Differentiable {
+struct Tensor<Scalar : FloatingPoint & Differentiable> : Differentiable {
   // NOTE: `value` must have type with known size (e.g. `Float`, not `Scalar`)
   // until differentiation has indirect passing support.
   var value: Float

test/AutoDiff/method.swift

@@ -45,7 +45,7 @@ extension Parameter {
   }
 }
 
-extension Parameter : Differentiable, VectorProtocol {
+extension Parameter : Differentiable, AdditiveArithmetic {
   typealias TangentVector = Parameter
   typealias Scalar = Float
   typealias Shape = ()
@@ -177,7 +177,7 @@ struct CustomParameter : Equatable {
   }
 }
 
-extension CustomParameter : Differentiable, VectorProtocol {
+extension CustomParameter : Differentiable, AdditiveArithmetic {
   typealias TangentVector = CustomParameter
   typealias Scalar = Float
   typealias Shape = ()

test/AutoDiff/protocol_requirement_autodiff.swift

@@ -18,7 +18,7 @@ extension DiffReq where TangentVector : AdditiveArithmetic {
   }
 }
 
-struct Quadratic : DiffReq, VectorProtocol {
+struct Quadratic : DiffReq, AdditiveArithmetic {
   typealias TangentVector = Quadratic
 
   @differentiable

test/AutoDiff/refcounting.swift

@@ -7,7 +7,7 @@ public class NonTrivialStuff : Equatable {
 }
 
 @frozen
-public struct Vector : AdditiveArithmetic, VectorProtocol, Differentiable, Equatable {
+public struct Vector : AdditiveArithmetic, Differentiable, Equatable {
   public var x: Float
   public var y: Float
   public var nonTrivialStuff = NonTrivialStuff()

test/AutoDiff/separate_tangent_type.swift

@@ -17,7 +17,7 @@ struct DifferentiableSubset : Differentiable {
   var b: Float
   @noDerivative var flag: Bool
 
-  struct TangentVector : Differentiable, VectorProtocol {
+  struct TangentVector : Differentiable, AdditiveArithmetic {
     typealias TangentVector = DifferentiableSubset.TangentVector
     var w: Float
     var b: Float

test/AutoDiff/simple_model.swift

@@ -13,7 +13,7 @@ struct DenseLayer : Equatable {
   let b: Float
 }
 
-extension DenseLayer : Differentiable, VectorProtocol {
+extension DenseLayer : Differentiable, AdditiveArithmetic {
   typealias TangentVector = DenseLayer
   typealias Scalar = Float
   static var zero: DenseLayer {
@@ -50,7 +50,7 @@ struct Model : Equatable {
   let l3: DenseLayer
 }
 
-extension Model : Differentiable, VectorProtocol {
+extension Model : Differentiable, AdditiveArithmetic {
   typealias TangentVector = Model
   typealias Scalar = Float
   static var zero: Model {

test/AutoDiff/simple_real_vector.swift

@@ -1,7 +1,7 @@
 // RUN: %target-swift-frontend -emit-silgen %s | %FileCheck %s
 
 @frozen
-public struct Vector : AdditiveArithmetic, VectorProtocol, Differentiable {
+public struct Vector : AdditiveArithmetic, Differentiable {
   public var x: Float
   public var y: Float
 

test/AutoDiff/witness_table_sil.swift

@@ -11,7 +11,7 @@ protocol Proto : Differentiable {
   func function3(_ x: Float, _ y: Double) -> Double
 }
 
-struct S : Proto, VectorProtocol {
+struct S : Proto, AdditiveArithmetic {
   typealias Scalar = Float
 
   @differentiable