Fix UBSan errors (left shift of negative value)

webrtc/modules/audio_coding/codecs/isac/fix/source/decode.c

Index: webrtc/modules/audio_coding/codecs/isac/fix/source/decode.c
diff --git a/webrtc/modules/audio_coding/codecs/isac/fix/source/decode.c b/webrtc/modules/audio_coding/codecs/isac/fix/source/decode.c
index e3de437a58ded933ab1edf68b4dd9b61bec2a4f0..cf2d507cb57fb3c72248d6ae13e59f2a7e7db6b0 100644
--- a/webrtc/modules/audio_coding/codecs/isac/fix/source/decode.c
+++ b/webrtc/modules/audio_coding/codecs/isac/fix/source/decode.c
@@ -182,7 +182,7 @@ int WebRtcIsacfix_DecodeImpl(int16_t* signal_out16,
 
     for (k = 0; k < FRAMESAMPLES/2; k++)
     {
-      Vector_Word32_1[k] = (Vector_Word16_2[k] * gainQ13) << 3;  // Q25
+      Vector_Word32_1[k] = (Vector_Word16_2[k] * gainQ13) * (1 << 3);  // Q25
     }
 
 
@@ -192,7 +192,7 @@ int WebRtcIsacfix_DecodeImpl(int16_t* signal_out16,
 
     /* --- Store Highpass Residual --- */
     for (k = 0; k < FRAMESAMPLES/2; k++)
-      Vector_Word32_1[k] = Vector_Word32_2[k] << 9;  // Q16 -> Q25
+      Vector_Word32_1[k] = Vector_Word32_2[k] * (1 << 9);  // Q16 -> Q25
 
     for( k = 0; k < PITCH_MAX_LAG + 10; k++ )
       (ISACdec_obj->plcstr_obj).prevHP[k] = Vector_Word32_1[FRAMESAMPLES/2 - (PITCH_MAX_LAG + 10) + k];