Crash in range coder for MC bitstreams in VoIP mode

Basic info

• Commit SHA: ab3c02d0
• Platform: Windows, MacOS

Bug description

Range coder fails (triggered assertion, MSAN uninitialized memory read) when decoding some MC bitstreams in VoIP mode.

Ways to reproduce

Failing MSAN job on Linux: https://forge.3gpp.org/rep/ivas-codec-pc/ivas-codec/-/jobs/50602

The specific condition that fails there is:

../IVAS_cod -mc 5_1 384000 48 testv/stv51MC48c.pcm bit
networkSimulator_g192 ../scripts/dly_error_profiles/dly_error_profile_5.dat bit netsimoutput tracefile_sim 2 0
../IVAS_dec -Tracefile tracefile_dec -VOIP 7_1_4 48 netsimoutput testv/stv51MC48c.pcm_MC51_384000_48-48_7_1_4_JBM5.tst

On Windows the following was also reported to fail:

../IVAS_cod.exe -mc 5_1 128000 48 input51.wav tmp51.g192
../scripts/tools/Win32/networkSimulator_g192.exe ../scripts/dly_error_profiles/dly_error_profile_5.dat tmp51.g192 tmp51_nw.g192 tracefile_sim 2 0
../IVAS_dec.exe -VOIP 5_1 48 tmp51_nw.g192 out51.wav
 
Frames processed:       Assertion failed: shifted_bit_buffer[i] <= 1, file \ivas-codec\lib_dec\ivas_range_uni_dec.c, line 499