Add divide to Sk2x, use native vdiv and vsqrt on ARM 64.

src/opts/Sk2x_none.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 // It is important _not_ to put header guards here.
 // This file will be intentionally included three times.
 
@@ skipping 25 matching lines @@
 
 M(Sk2x<T>) add(const Sk2x<T>& o) const {
     return Sk2x<T>(fVec[0] + o.fVec[0], fVec[1] + o.fVec[1]);
 }
 M(Sk2x<T>) subtract(const Sk2x<T>& o) const {
     return Sk2x<T>(fVec[0] - o.fVec[0], fVec[1] - o.fVec[1]);
 }
 M(Sk2x<T>) multiply(const Sk2x<T>& o) const {
     return Sk2x<T>(fVec[0] * o.fVec[0], fVec[1] * o.fVec[1]);
 }
+M(Sk2x<T>) divide(const Sk2x<T>& o) const {
+    return Sk2x<T>(fVec[0] / o.fVec[0], fVec[1] / o.fVec[1]);
+}
 
 M(Sk2x<T>) Min(const Sk2x<T>& a, const Sk2x<T>& b) {
     return Sk2x<T>(SkTMin(a.fVec[0], b.fVec[0]), SkTMin(a.fVec[1], b.fVec[1]));
 }
 M(Sk2x<T>) Max(const Sk2x<T>& a, const Sk2x<T>& b) {
     return Sk2x<T>(SkTMax(a.fVec[0], b.fVec[0]), SkTMax(a.fVec[1], b.fVec[1]));
 }
 
 #undef M
 
 #define M template <> inline
 
 M Sk2f Sk2f::rsqrt() const { return Sk2f(sk_float_rsqrt(fVec[0]), sk_float_rsqrt(fVec[1])); }
 M Sk2f Sk2f:: sqrt() const { return Sk2f(         sqrtf(fVec[0]),          sqrtf(fVec[1])); }
 
 M Sk2d Sk2d::rsqrt() const { return Sk2d(1.0/::sqrt(fVec[0]), 1.0/::sqrt(fVec[1])); }
 M Sk2d Sk2d:: sqrt() const { return Sk2d(    ::sqrt(fVec[0]),     ::sqrt(fVec[1])); }
 
 #undef M
 
 #endif