Resolve "Replace Overflow BASOP-Operators by overflow-free variants in lib_dec"

Closes #1866 (closed)

//??sat marking where saturation variant of overflow operator was put out of uncertainty

FILE	STATUS
lib_dec/ACcontextMapping_dec_fx.c	NO NEED
lib_dec/FEC_HQ_core_fx.c	DONE
lib_dec/FEC_HQ_phase_ecu_fx.c	DONE
lib_dec/FEC_fx.c	DONE
lib_dec/LD_music_post_filter_fx.c	DONE
lib_dec/TonalComponentDetection_fx.c	NO NEED
lib_dec/acelp_core_switch_dec_fx.c	DONE
lib_dec/ari_dec_fx.c	NO NEED
lib_dec/arith_coder_dec_fx.c	DONE - kept L_macNs_co
lib_dec/avq_dec_fx.c	NO NEED
lib_dec/bass_psfilter_fx.c	NO NEED
lib_dec/cng_dec_fx.c	DONE
lib_dec/core_switching_dec_fx.c	DONE
lib_dec/dec_higher_acelp_fx.c	DONE
lib_dec/dec_pit_exc_fx.c	DONE
lib_dec/dec_post_fx.c	DONE
lib_dec/dec_tcx_fx.c	DONE - kept a few L_macNs_co
lib_dec/er_dec_acelp_fx.c	NO NEED
lib_dec/er_dec_tcx_fx.c	DONE - kept some L_macNs_co
lib_dec/er_scale_syn_fx.c	DONE
lib_dec/er_sync_exc_fx.c	DONE
lib_dec/er_util_fx.c	DONE
lib_dec/evs_dec_fx.c	DONE
lib_dec/fd_cng_dec_fx.c	DONE - kept L_add_co/L_macNs_co
lib_dec/gain_dec_fx.c	DONE
lib_dec/gs_dec_amr_wb_fx.c	DONE - kept all Overflows
lib_dec/hf_synth_fx.c	DONE
lib_dec/igf_dec_fx.c	DONE - kept L_add_co/L_macNs_co
lib_dec/ivas_core_dec_fx.c	DONE
lib_dec/ivas_mc_param_dec_fx.c	NO NEED
lib_dec/ivas_out_setup_conversion_fx.c	NO NEED
lib_dec/ivas_sba_dirac_stereo_dec_fx.c	NO NEED
lib_dec/ivas_stereo_cng_dec_fx.c	NO NEED
lib_dec/ivas_stereo_switching_dec_fx.c	NO NEED
lib_dec/jbm_jb4_jmf_fx.c	NO NEED
lib_dec/jbm_pcmdsp_apa_fx.c	NO NEED
lib_dec/lsf_dec_fx.c	NO NEED
lib_dec/nelp_dec_fx.c	NO NEED
lib_dec/pitch_extr_fx.c	DONE
lib_dec/post_dec_fx.c	DONE
lib_dec/pvq_core_dec_fx.c	DONE
lib_dec/pvq_decode_fx.c	DONE
lib_dec/swb_bwe_dec_hr_fx.c	NO NEED
lib_dec/swb_tbe_dec_fx.c	DONE
lib_dec/syn_outp_fx.c	DONE
lib_dec/tcq_core_dec_fx.c	NO NEED
lib_dec/tonalMDCTconcealment_fx.c	DONE
lib_dec/transition_dec_fx.c	DONE
lib_dec/waveadjust_fec_dec_fx.c	NO NEED