Avoid left-shifting negative values in a number of places

webrtc/common_audio/signal_processing/vector_scaling_operations.c

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE 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.
  */
 
@@ skipping 19 matching lines @@
     if (right_shifts > 0)
     {
         for (i = length; i > 0; i--)
         {
             (*res++) = ((*in++) >> right_shifts);
         }
     } else
     {
         for (i = length; i > 0; i--)
         {
-            (*res++) = ((*in++) << (-right_shifts));
+            (*res++) = ((*in++) * (1 << (-right_shifts)));
         }
     }
 }
 
 void WebRtcSpl_VectorBitShiftW32(int32_t *out_vector,
                                  size_t vector_length,
                                  const int32_t *in_vector,
                                  int16_t right_shifts)
 {
     size_t i;
@@ skipping 105 matching lines @@
   }
 
   for (i = 0; i < length; i++) {
     out_vector[i] = (int16_t)((
         in_vector1[i] * in_vector1_scale + in_vector2[i] * in_vector2_scale +
         round_value) >> right_shifts);
   }
 
   return 0;
 }