[regression] Encoder crash for Stereo at 24.4 kbps
# Basic info
<!--- Add commit SHA used to reproduce -->
- Float reference:
- Encoder (float):
- Decoder (float):
- Fixed point:
- Encoder (fixed): c84243d163646048b8883bad31627b15588a72e8
- Decoder (fixed):
# Bug description
The fixed point encoder crashes with an assert:
```
Assertion failed: (0), function L_add, file basop32.c, line 1661.
```
# Ways to reproduce
Box folder: ...\Box_EXTERNAL_IVAS_BASOP_VERIFICATION\issues\issue-1289
<!-- Commandline or script -->
```bash
./IVAS_cod_fx -stereo -max_band FB 24400 48 stereo-noisy_speech-p800-1-cat1-lab_a-20ms_aligned_files_concatenated_48.10dB.wav bit
```
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issue