Don't let the compiler complain that |a| is uninit

src/core/SkColorSpaceXform.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkColorPriv.h"
 #include "SkColorSpace_Base.h"
 #include "SkColorSpacePriv.h"
@@ skipping 635 matching lines @@
           srcTables[1][(src[2] >>  8) & 0xFF],
           srcTables[1][(src[3] >>  8) & 0xFF], };
     b = { srcTables[2][(src[0] >> 16) & 0xFF],
           srcTables[2][(src[1] >> 16) & 0xFF],
           srcTables[2][(src[2] >> 16) & 0xFF],
           srcTables[2][(src[3] >> 16) & 0xFF], };
     a = (1.0f / 255.0f) * SkNx_cast<float>(Sk4u::Load(src) >> 24);
 }
 
 static inline void load_rgb_linear(const uint32_t* src,
-                                   Sk4f& r, Sk4f& g, Sk4f& b, Sk4f&,
+                                   Sk4f& r, Sk4f& g, Sk4f& b, Sk4f& a,
                                    const float* const[3]) {
     r = (1.0f / 255.0f) * SkNx_cast<float>((Sk4u::Load(src)      ) & 0xFF);
     g = (1.0f / 255.0f) * SkNx_cast<float>((Sk4u::Load(src) >>  8) & 0xFF);
     b = (1.0f / 255.0f) * SkNx_cast<float>((Sk4u::Load(src) >> 16) & 0xFF);
+    a = 0.0f; // Don't let the compiler complain that |a| is uninitialized.
 }
 
 static inline void load_rgba_linear(const uint32_t* src,
                                     Sk4f& r, Sk4f& g, Sk4f& b, Sk4f& a,
                                     const float* const[3]) {
     r = (1.0f / 255.0f) * SkNx_cast<float>((Sk4u::Load(src)      ) & 0xFF);
     g = (1.0f / 255.0f) * SkNx_cast<float>((Sk4u::Load(src) >>  8) & 0xFF);
     b = (1.0f / 255.0f) * SkNx_cast<float>((Sk4u::Load(src) >> 16) & 0xFF);
     a = (1.0f / 255.0f) * SkNx_cast<float>((Sk4u::Load(src) >> 24)       );
 }
@@ skipping 657 matching lines @@
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 std::unique_ptr<SkColorSpaceXform> SlowIdentityXform(const sk_sp<SkColorSpace>& space) {
         return std::unique_ptr<SkColorSpaceXform>(new SkColorSpaceXform_Base
                 <kTable_SrcGamma, kTable_DstGamma, kNone_ColorSpaceMatch>
                 (space, SkMatrix::I(), space));
 }