ec_enc_shrink() assertion failure
When encoding an Opus hybrid frame with redundancy, no space is reserved for the 21 bits needed to signal redundancy, which can lead to SILK using too many bits and an assertion failure in ec_enc_shrink().
The issue can be reproduced with libopus from git master (4667b699).
$ ./configure --enable-assertions --enable-fixed-point --disable-shared
$ make
$ gcc -g ec_enc_shrink_assert.c -Iinclude .libs/libopus.a -lm
$ ./a.out
data_len=10 toc=08
data_len=80 toc=6b 83
Fatal (internal) error in celt/entenc.c, line 238: assertion failed: _this->offs+_this->end_offs<=_size