So can be used with language wrappers

It was testing an old version of freebsd and now it's image is gone.
We really like to test the environment.

Fixed at 6977a95f

Fixes fuzzer issue.

To block template argument deduction.

Also move the implementation of some methods from the .cc to the .hh

Add unit test and integration test

selection of which name records to keep in the subset method.

elements and serialize method

string

https://github.com/harfbuzz/harfbuzz/issues/1633#issuecomment-485764140

Something's phishy about hb_sorted_array_t<>.  Can't get it work nicely with
change I'm making.  Ugh..

To check for assignment overflows.