Fix up AdditiveArithmetic conformance.

Author: bartchr808

stdlib/public/core/SIMDVector.swift

@@ -1221,7 +1221,7 @@ extension SIMD where Scalar: FloatingPoint {
 
   @_transparent
   // SWIFT_ENABLE_TENSORFLOW
-  @differentiable(vjp: _vjpAdd(lhs:rhs:)
+  @differentiable(vjp: _vjpSubtract(lhs:rhs:)
     where Self : Differentiable,
           Self.TangentVector : SIMD,
           Scalar : Differentiable & BinaryFloatingPoint,
@@ -1269,7 +1269,7 @@ extension SIMD where Scalar: FloatingPoint {
 
   @_transparent
   // SWIFT_ENABLE_TENSORFLOW
-  @differentiable(vjp: _vjpAdd(lhs:rhs:)
+  @differentiable(vjp: _vjpSubtract(lhs:rhs:)
     where Self : Differentiable,
           Self.TangentVector : SIMD,
           Scalar : Differentiable & BinaryFloatingPoint,
@@ -1303,16 +1303,6 @@ extension SIMD where Scalar: FloatingPoint {
     return lhs / Self(repeating: rhs)
   }
 
-//  @_transparent
-//  public static func +=(lhs: inout Self, rhs: Self) {
-//    lhs = lhs + rhs
-//  }
-
-//  @_transparent
-//  public static func -=(lhs: inout Self, rhs: Self) {
-//    lhs = lhs - rhs
-//  }
-  
   @_transparent
   public static func *=(lhs: inout Self, rhs: Self) {
     lhs = lhs * rhs
@@ -1323,11 +1313,6 @@ extension SIMD where Scalar: FloatingPoint {
     lhs = lhs / rhs
   }
 
-//  @_transparent
-//  public static func *=(lhs: inout Self, rhs: Scalar) {
-//    lhs = lhs * rhs
-//  }
-  
   @_transparent
   public static func +=(lhs: inout Self, rhs: Scalar) {
     lhs = lhs + rhs
@@ -1337,6 +1322,11 @@ extension SIMD where Scalar: FloatingPoint {
   public static func -=(lhs: inout Self, rhs: Scalar) {
     lhs = lhs - rhs
   }
+
+  @_transparent
+  public static func *=(lhs: inout Self, rhs: Scalar) {
+    lhs = lhs * rhs
+  }
 
   @_transparent
   public static func /=(lhs: inout Self, rhs: Scalar) {

stdlib/public/core/SIMDVectorTypes.swift.gyb

@@ -192,8 +192,6 @@ extension SIMD${n} where Scalar: BinaryFloatingPoint {
 // SWIFT_ENABLE_TENSORFLOW
 extension SIMD${n} : AdditiveArithmetic where Scalar : FloatingPoint {}
 
-//extension SIMD${n} : VectorNumeric where Scalar : FloatingPoint {}
-
 extension SIMD${n} : Differentiable
   where Scalar : Differentiable & BinaryFloatingPoint,
         Scalar.TangentVector: BinaryFloatingPoint {