skip neon code in libwebp when neon is explicitly unavailable

third_party/libwebp/dsp/enc.c

 // Copyright 2011 Google Inc. All Rights Reserved.
 //
 // Use of this source code is governed by a BSD-style license
 // that can be found in the COPYING file in the root of the source
 // tree. An additional intellectual property rights grant can be found
 // in the file PATENTS. All contributing project authors may
 // be found in the AUTHORS file in the root of the source tree.
 // -----------------------------------------------------------------------------
 //
 // Speed-critical encoding functions.
@@ skipping 671 matching lines @@
 VP8Metric VP8SSE16x16;
 VP8Metric VP8SSE8x8;
 VP8Metric VP8SSE16x8;
 VP8Metric VP8SSE4x4;
 VP8WMetric VP8TDisto4x4;
 VP8WMetric VP8TDisto16x16;
 VP8QuantizeBlock VP8EncQuantizeBlock;
 VP8BlockCopy VP8Copy4x4;
 
 extern void VP8EncDspInitSSE2(void);
+#if defined(WEBP_USE_NEON)
 extern void VP8EncDspInitNEON(void);
+#endif
 
 void VP8EncDspInit(void) {
   InitTables();
 
   // default C implementations
   VP8CollectHistogram = CollectHistogram;
   VP8ITransform = ITransform;
   VP8FTransform = FTransform;
   VP8ITransformWHT = ITransformWHT;
   VP8FTransformWHT = FTransformWHT;
@@ skipping 19 matching lines @@
     if (VP8GetCPUInfo(kNEON)) {
       VP8EncDspInitNEON();
     }
 #endif
   }
 }
 
 #if defined(__cplusplus) || defined(c_plusplus)
 }    // extern "C"
 #endif