harmonization of the 0 bit bwe between EVS and IVAS
# Basic info
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- Float reference:
- Encoder (float):
- Decoder (float):
- Fixed point:
- Encoder (fixed): a0051869
- Decoder (fixed):
# Bug description
This will include hf_synth_ivas_fx, hf_synthesis_ivas_fx. Part of hf_synth_ivas_fx() will be preserved as it prevent saturation, which also means hp400_12k8_ivas_fx will be preserved too.
# Ways to reproduce
Box folder: ...\\Box_EXTERNAL_IVAS_BASOP_VERIFICATION\\issues\\issue-xxxx
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```bash
```
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issue