jsc: Heap-buffer-overflow in JSC::IndexingHeader::vectorLength

Detailed report: https://oss-fuzz.com/testcase?key=5694527739265024 Project: jsc Fuzzer: jsfuzzer Job Type: asanjsc Platform Id: linux Crash Type: Heap-buffer-overflow READ 4 Crash Address: 0x62d000060004 Crash State: JSC::IndexingHeader::vectorLength JSC::Butterfly::computeIndexingMask...