USAN: out-of-bounds-index in lib_dec/dec_acelp.c:175:19
### Basic Info
- Commit SHA: 6bdf4359ccc7bd69d267b699b19c63fdc3deb1ae
### Bug description
Clang USAN found an out-of-bounds-index error at lib_dec/dec_acelp.c:175:19:
```
lib_dec/dec_acelp.c:175:19: runtime error: index -1 out of bounds for type 'const uint32_t [9]'
#0 0x104b2ae in D_ACELP_indexing /builds/rep/ivas-codec-pc/ivas-codec/lib_dec/dec_acelp.c:175:19
#1 0x748f53 in inov_decode /builds/rep/ivas-codec-pc/ivas-codec/lib_dec/inov_dec.c:130:21
#2 0x10aac9c in decod_tran /builds/rep/ivas-codec-pc/ivas-codec/lib_dec/dec_tran.c:118:9
#3 0xff4df1 in acelp_core_dec /builds/rep/ivas-codec-pc/ivas-codec/lib_dec/acelp_core_dec.c:794:17
#4 0x1126f0f in ivas_core_dec /builds/rep/ivas-codec-pc/ivas-codec/lib_dec/ivas_core_dec.c:353:28
#5 0xaad27a in ivas_sce_dec /builds/rep/ivas-codec-pc/ivas-codec/lib_dec/ivas_sce_dec.c:243:20
#6 0x807034 in ivas_jbm_dec_tc /builds/rep/ivas-codec-pc/ivas-codec/lib_dec/ivas_jbm_dec.c:228:28
#7 0x4664d3 in IVAS_DEC_GetSamplesDecoder /builds/rep/ivas-codec-pc/ivas-codec/lib_dec/lib_dec.c:1189:28
#8 0x445bec in decodeG192 /builds/rep/ivas-codec-pc/ivas-codec/apps/decoder.c:2601:32
#9 0x42ce7b in main /builds/rep/ivas-codec-pc/ivas-codec/apps/decoder.c:790:17
#10 0x7fdc57af8d8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
#11 0x7fdc57af8e3f in __libc_start_main csu/../csu/libc-start.c:392:3
#12 0x405804 in _start (/builds/rep/ivas-codec-pc/ivas-codec/IVAS_dec+0x405804)
SUMMARY: UndefinedBehaviorSanitizer: out-of-bounds-index lib_dec/dec_acelp.c:175:19 in
```
### How to reproduce
Build with
```
make clean
make -j CLANG=3
export UBSAN_OPTIONS=report_error_type=1,print_stacktrace=1
```
Then run
```
IVAS_cod -dtx -sba 1 scripts/switchPaths/sw_13k2_192k_50fr.bin 32 scripts/testv/stvFOA32n.wav tests/ref/param_file/enc/stvFOA32n.wav_SBA_FOA_bitrate_switching_from_13_2_kbps_to_192_kbps_32kHz_in_32kHz_out_DTX_on_EXT_out.192
IVAS_dec -fr 10 EXT 32 stvFOA32n.wav_SBA_FOA_bitrate_switching_from_13_2_kbps_to_192_kbps_32kHz_in_32kHz_out_DTX_on_EXT_out.192 stvFOA32n.wav_SBA_FOA_bitrate_switching_from_13_2_kbps_to_192_kbps_32kHz_in_32kHz_out_DTX_on_EXT_out.dec.wav
```
or
```
python3 -m pytest "test_param_file_tests[stv-SBA FOA bitrate switching from 13.2 kbps to 192 kbps, 32kHz in, 32kHz out, DTX on, EXT out]" -n auto --update_ref --ref_encoder_path ./IVAS_cod --ref_decoder_path ./IVAS_dec
```
issue