vterm_lookup_encoding
state->encoding_utf8.enc = vterm_lookup_encoding(ENC_UTF8, 'u');
vterm_lookup_encoding(ENC_UTF8, 'u') :
vterm_lookup_encoding(ENC_SINGLE_94, 'B');
VTermEncoding *newenc = vterm_lookup_encoding(ENC_SINGLE_94, bytes[1]);
VTermEncoding *vterm_lookup_encoding(VTermEncodingType type, char designation);