Apple WebKit / Safari 10.0.2(12602.3.12.0.1) - 'PrototypeMap::createEmptyStructure' Universal Cross-Site Scripting

jsCallee // newTarget may be an InternalFunction if we were called from Reflect.construct. JSFunction targetFunction = jsDynamicCastnewTarget; if LIKELYtargetFunction ... return targetFunction-rareDatavm-createInternalFunctionAllocationStructureFromBasevm, prototype, baseClass; ... else ... retur...