avcodec/aacdec_fixed: Fix integer overflow in apply_dependent_coupling_fixed()

Fixes: runtime error: signed integer overflow: 623487 * 536870912 cannot be represented in type 'int'
Fixes: 3594/clusterfuzz-testcase-minimized-4650622935629824

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 41d96af2a7)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/aacdec_fixed.c

@@ -394,7 +394,7 @@ static void apply_dependent_coupling_fixed(AACContext *ac,
                         for (k = offsets[i]; k < offsets[i + 1]; k++) {
                             tmp = (int)(((int64_t)src[group * 128 + k] * c + \
                                         (int64_t)0x1000000000) >> 37);
-                            dest[group * 128 + k] += tmp * (1 << shift);
+                            dest[group * 128 + k] += tmp * (1U << shift);
                         }
                     }
                 }