OSV-2020-2179 Heap-buffer-overflow in arrow::internal::ValidateUTF8

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=27731 Crash type: Heap-buffer-overflow READ 8 Crash state: arrow::internal::ValidateUTF8 arrow::internal::ValidateArrayFullImpl::ValidateWithType arrow::internal::ValidateArrayFullImpl::Visit...