OSV-2018-73 Stack-buffer-overflow in hb_array_t<char const>::cmp

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=11908 Crash type: Stack-buffer-overflow READ 4 Crash state: hbarrayt::cmp OT::post::acceleratort::cmpkey hbbsearchr...