By Cameron French TORONTO (Reuters) – Noah Baumbach’s “While We’re Young” and Ed Zwick’s “Pawn Sacrifice” will be among the world premieres at this year’s Toronto International Film Festival, one of the top movie showcases and a favored platform to unveil Oscar contenders. “While We’re Young”, by indie darling Baumbach, stars Ben Stiller and Naomi Watts as a middle aged couple whose lives are disrupted when a free-spirited younger couple enters the picture. “Pawn Sacrifice” stars Tobey Maguire as American chess legend Bobby Fischer, locked in a world championship match in 1972 with Soviet rival Boris Spassky, played by Liev Schreiber.