Re-implemented & repurposed CFF:remap_t as hb_map2_t (moved to hb-ot-layout-common.hh) for two-way mapping for use by index map subsetting.
Hooked up HVAR subsetter through _subset2.
Some renaming in CFF code.
Rewrote struct FDSelect3_4.ranges as ArrayOf
Updated FDSelect3_4::sanitize () to call ranges.sanitize ()
nRanges now a function to return a reference to ranges.len
* reimplement ByteStr as byte_str_t based on hb_ubytes_t
Unuse start_embed<ByteStr>
Also renamed SubByteStr to byte_str_ref_t
More renaming to come
* substr renamed to str_ref in line with its type byte_str_ref_t
* uncamelize non-table struct names
* uncamelized non-struct types OpCode etc
* add byte_str_t copy ctor
* test
* test2
* undo tests
* fix bot failure
* undo the previous change
* fixed tabs, added inline
* Revert "fixed tabs, added inline"
This reverts commit 21163c30e9.
* fix tabs
Michiharu Ariza
Behdad Esfahbod