JSC BytecodeGenerator::emitEqualityOpImpl Data Mishandling

JSC: A bug in BytecodeGenerator::emitEqualityOpImpl Related CVE Numbers: CVE-2019-8684. PoC: let a = 1 || typeof 1 === 'string'; Generated bytecode: BPmgTo:0x7ff1965a0000-0x7ff1965a8000, NoneGlobal, 37: 11 instructions 0 wide instructions, 2 instructions with metadata; 225 bytes 188 metadata byte...