Fix UBSan errors (left shift of negative value)

webrtc/modules/audio_coding/codecs/ilbc/do_plc.c

 /*
  *  Copyright (c) 2011 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 101 matching lines @@
 
         shift2 = WebRtcSpl_GetSizeInBits(ener)-15;
         measure = (int16_t)WEBRTC_SPL_SHIFT_W32(ener, -shift2) * crossSquare;
 
         shift3 = WebRtcSpl_GetSizeInBits(ener_comp)-15;
         maxMeasure = (int16_t)WEBRTC_SPL_SHIFT_W32(ener_comp, -shift3) *
             crossSquareMax;
 
         /* Calculate shift value, so that the two measures can
            be put in the same Q domain */
-        if(((shiftMax<<1)+shift3) > ((shift1<<1)+shift2)) {
-          tmp1 = WEBRTC_SPL_MIN(31, (shiftMax<<1)+shift3-(shift1<<1)-shift2);
+        if(2 * shiftMax + shift3 > 2 * shift1 + shift2) {
+          tmp1 =
+              WEBRTC_SPL_MIN(31, 2 * shiftMax + shift3 - 2 * shift1 - shift2);
           tmp2 = 0;
         } else {
           tmp1 = 0;
-          tmp2 = WEBRTC_SPL_MIN(31, (shift1<<1)+shift2-(shiftMax<<1)-shift3);
+          tmp2 =
+              WEBRTC_SPL_MIN(31, 2 * shift1 + shift2 - 2 * shiftMax - shift3);
         }
 
         if ((measure>>tmp1) > (maxMeasure>>tmp2)) {
           /* New lag is better => record lag, measure and domain */
           lag = j;
           crossSquareMax = crossSquare;
           cross = cross_comp;
           shiftMax = shift1;
           ener = ener_comp;
         }
@@ skipping 158 matching lines @@
     iLBCdec_inst->consPLICount = 0;
   }
 
   /* update state */
   iLBCdec_inst->prevPLI = PLI;
   WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->prevLpc, PLClpc, (LPC_FILTERORDER+1));
   WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->prevResidual, PLCresidual, iLBCdec_inst->blockl);
 
   return;
 }