Compress glyf table generically if it fails specifically

[behdad]

I'm trying to compress fonts with new formats of glyf table that I'm developing. It currently fails. I expect it to compress the glyf table as a generic table with brotli instead.

[behdad]

The library code allows disabling it:

woff2/include/woff2/encode.h

Line 24 in 4721483

bool allow_transforms;