iSAC fix entropy coder: Recently added DCHECK could in fact trigger

webrtc/common_audio/signal_processing/include/spl_inl.h

Index: webrtc/common_audio/signal_processing/include/spl_inl.h
diff --git a/webrtc/common_audio/signal_processing/include/spl_inl.h b/webrtc/common_audio/signal_processing/include/spl_inl.h
index 370834e694096ca0e76f388d4c115aa2e275f702..812ab2d5875e7dc84f86f001829a4bae9d32e1d3 100644
--- a/webrtc/common_audio/signal_processing/include/spl_inl.h
+++ b/webrtc/common_audio/signal_processing/include/spl_inl.h
@@ -63,6 +63,11 @@ static __inline int WebRtcSpl_CountLeadingZeros64(uint64_t n) {
 #endif
 }
 
+static __inline int32_t WebRtcSpl_SatW64ToW32(int64_t x) {
+  int32_t x32 = (int32_t)x;
+  return x32 == x ? x32 : x < 0 ? INT32_MIN : INT32_MAX;
+}
+
 #ifdef WEBRTC_ARCH_ARM_V7
 #include "webrtc/common_audio/signal_processing/include/spl_inl_armv7.h"
 #else