Preserving 24-bit accuracy for fixed-point encoder

celt/arch.h

celt/celt.h

celt/celt_encoder.c

celt/mathops.h

silk/API.h

silk/enc_API.c

src/mapping_matrix.c

src/mapping_matrix.h

src/opus_encoder.c

src/opus_multistream_encoder.c

src/opus_private.h

src/opus_projection_encoder.c

tests/test_opus_projection.c