OSV-2020-54 Heap-buffer-overflow in OT::HintingDevice* hb_serialize_context_t::embed<OT::HintingDevice>

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20211 Crash type: Heap-buffer-overflow READ Crash state: OT::HintingDevice hbserializecontextt::embed OT::HintingDevice::copy OT::Device::copy...