elements and serialize method

string

Part of https://github.com/harfbuzz/harfbuzz/issues/1652

Part of https://github.com/harfbuzz/harfbuzz/issues/1553

In file included from hb-ot-name.cc:29:
hb-ot-name-table.hh: In member function 'unsigned int OT::name::get_size() const':
hb-ot-name-table.hh:157: error: ISO C++ says that these are ambiguous, even though the worst conversion for the first is better than the worst conversion for the second:
hb-open-type.hh:354: note: candidate 1: const Type& OT::UnsizedArrayOf<Type>::operator[](unsigned int) const [with Type = OT::NameRecord]
hb-ot-name-table.hh:157: note: candidate 2: operator[](const T*, int) <built-in>
hb-ot-name-table.hh: In member function 'void OT::name::accelerator_t::init(hb_face_t*)':
hb-ot-name-table.hh:196: error: ISO C++ says that these are ambiguous, even though the worst conversion for the first is better than the worst conversion for the second:
hb-dsalgs.hh:574: note: candidate 1: Type& hb_array_t<Type>::operator[](unsigned int) const [with Type = const OT::NameRecord]
hb-ot-name-table.hh:196: note: candidate 2: operator[](T*, int) <built-in>
hb-ot-name-table.hh:197: error: ISO C++ says that these are ambiguous, even though the worst conversion for the first is better than the worst conversion for the second:
hb-dsalgs.hh:574: note: candidate 1: Type& hb_array_t<Type>::operator[](unsigned int) const [with Type = const OT::NameRecord]
hb-ot-name-table.hh:197: note: candidate 2: operator[](T*, int) <built-in>
hb-ot-name-table.hh:198: error: ISO C++ says that these are ambiguous, even though the worst conversion for the first is better than the worst conversion for the second:
hb-dsalgs.hh:574: note: candidate 1: Type& hb_array_t<Type>::operator[](unsigned int) const [with Type = const OT::NameRecord]
hb-ot-name-table.hh:198: note: candidate 2: operator[](T*, int) <built-in>
make[4]: *** [libharfbuzz_la-hb-ot-name.lo] Error 1
make[3]: *** [all-recursive] Error 1

Use in a couple of places.  Push to bots to see how many unhappy before
I convert the rest.

Fixes all except for cmap.  To be done separately.

Part of https://github.com/harfbuzz/harfbuzz/issues/1146

https://github.com/harfbuzz/harfbuzz/pull/1254

https://github.com/harfbuzz/harfbuzz/commit/d941f66c75fe26f909b1ba248535cc372bbde851#commitcomment-31076011

This is like hb_script_t.

We had this exposed as unsigned int since 2.0.0 release in two APIs,
as well as hb_ot_layout_get_size_params() from earlier.
But since no one uses those (right?!), let's just fix this now.

Accept Mac Latin name entries as ASCII as well.

It assumes all names are encoded in UTF16-BE.  Other than that, and not
listing languages correctly, it's *supposed* to work.

Fix a bug in CBDT sanitize, and redundant check in avar.

Sorry for the noise, downstream custom builders.  Please adjust.