The playwright has died of liver cancer only a few months after announcing the diagnosis. “Radio Golf,” the last of the 10 plays that constitute Mr. Wilson’s majestic theatrical cycle, opened at the Yale Repertory Theater last spring and has subsequently been produced in Los Angeles. It was the concluding chapter in a spellbinding story that began more than two decades ago, when Mr. Wilson’s play “Ma Rainey’s Black Bottom” had its debut at the same theater, in 1984, and announced the arrival of a major talent, fully matured.”