Part of https://github.com/harfbuzz/harfbuzz/issues/630

This was causing problem on systems without visibility when map was used
from both libharfbuzz and libharfbuzz-subset. Sigh.

https://ci.appveyor.com/project/harfbuzz/harfbuzz/build/1.0.1669/job/dey47nmff0770vp3

Some of the build bots, still fail on this.  I suppose mine pass because
I enable C++11...

Anyway, remove these again.

Sigh.

This reverts commit ff92de76.

Revert that and remove ASSERT_POD. Let's see which bots are
unhappy with this configuration...

Null() and Crap() are only places that there's no space before '('...

llvm-gcc-4.2 bot had this problem:
hb-private.hh:812: error: initializer specified for non-virtual method 'void hb_vector_t<Type, StaticSize>::operator=(const hb_vector_t<Type, StaticSize>&) [with Type = hb_user_data_array_t::hb_user_data_item_t, unsigned int StaticSize = 1u]'

Removing the delete didn't work with a constructor. So, remove constructor.
Just disallow assignment.  Still better than nothing.

Clang build was failing with:

/usr/bin/ld: .libs/libharfbuzz_la-hb-blob.o: relocation R_X86_64_PC32 against undefined hidden symbol `_ZTH12_hb_CrapPool' can not be used when making a shared object

Instead of fighting it, just disable use of it.

If a pointer type was passed to Null(), reinterpret_cast<> was
complaining about qualifiers being removed. Turns out I need the const on
the other side of "Type" to fix that.  Also remove unused const from
NullPool type.

Not sure if I like to keep it. For now, aim for correctness.

Common Regoin for Access Protection.  Like the NullPool, but writable.

Makes for cleaner code.

Fixup for previous commit. Was accidentally turned off.

Make clang happy. Also, don't use anonymous union.

We'll see if this sticks to the bots.

Seems like I messed up; buffer overrun got reported.

Part of https://github.com/harfbuzz/harfbuzz/issues/1017

Part of https://github.com/harfbuzz/harfbuzz/issues/1017

For consistency.

Obviously one can use a newer NDK for building an updated HarfBuzz
instead that now pretty old version however I am concerned if that
version checking is working with clang that is used with the newer
NDK versions.

Fixes https://github.com/harfbuzz/harfbuzz/issues/901