SEOUL, South Korea — South Korea’s Supreme Court has upheld a controversial 1989 ruling that acquitted the owner of a massive institution that housed vagrants, children and the disabled of serious charges despite the enslavement and abuse of thousands of those trapped there in the 1960s, 1970s and 1980s. Thursday’s decision was a setback for survivors who have been seeking justice for their plight as well as compensation. No one yet has been held accountable for the deaths, rapes, beatings and forced work that took place at the state-funded Brothers Home in Busan, abuses that were documented by an Associated Press report in 2016.