Remove overly-promiscuous SkNx syntax sugar.

src/core/SkGeometry.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGeometry.h"
 #include "SkMatrix.h"
 #include "SkNx.h"
@@ skipping 1266 matching lines @@
     Sk2s ww(fW);
     Sk2s one(1);
 
     Sk2s p1w = p1 * ww;
     Sk2s C = p0;
     Sk2s A = p2 - times_2(p1w) + p0;
     Sk2s B = times_2(p1w - C);
     Sk2s numer = quad_poly_eval(A, B, C, tt);
 
     B = times_2(ww - one);
-    A = -B;
+    A = Sk2s(0)-B;
     Sk2s denom = quad_poly_eval(A, B, one, tt);
 
     return to_point(numer / denom);
 }
 
 SkVector SkConic::evalTangentAt(SkScalar t) const {
     Sk2s p0 = from_point(fPts[0]);
     Sk2s p1 = from_point(fPts[1]);
     Sk2s p2 = from_point(fPts[2]);
     Sk2s ww(fW);
@@ skipping 281 matching lines @@
         matrix.preScale(SK_Scalar1, -SK_Scalar1);
     }
     if (userMatrix) {
         matrix.postConcat(*userMatrix);
     }
     for (int i = 0; i < conicCount; ++i) {
         matrix.mapPoints(dst[i].fPts, 3);
     }
     return conicCount;
 }