Missing instance records in fvar::Table

[zimond]

related #120.

I think based on the spec, there are instance records in fvar. But currently ttf-parser only parses axis record?

[RazrFalcon]

Yes, it is not implemented.

[zimond]

@RazrFalcon do you mind if I submit a PR for this?

[RazrFalcon]

Sure. Note that the PostScript name field is optional, making parsing more convoluted, since you cannot use read_array16

You can check it using:

let has_post_script_name = instance_length == (axes_count * 4) + 6;

I guess the only way to implement it is by creating a custom wrapper for InstanceRecords data blob with a get method that will do the parsing.