static_assert on m68k-buildroot-linux-uclibc

[bkuhls]

Building harfbuzz 2.5.3 fails:

hb-pool.hh: In instantiation of ‘struct hb_pool_t<hb_serialize_context_t::object_t>’:
hb-serialize.hh:460:23:   required from here
hb-pool.hh:80:3: error: static assertion failed
   static_assert (alignof (T) % sizeof (void *) == 0, "");

using this toolchain

$ /home/buildroot/br4/output/host/bin/m68k-linux-g++ -v
Target: m68k-buildroot-linux-uclibc
gcc version 7.4.0 (Buildroot 2019.05.1) 

The error was caught by the buildroot autobuilders:
http://autobuild.buildroot.net/?reason=harfbuzz-2.5.3
http://autobuild.buildroot.net/results/121/121891c54f1f6ba3661bacdeb054aab56129d3e5/build-end.log

[behdad]

I pushed a change. Please test and confirm if it fixes. Thanks.

[bkuhls]

Bug is solved, thx!