Those who have seen “MADE IN THE U.S.A.,” a traveling exhibition organized by the University Art Museum, Berkeley, agree that what makes the show especially worthwhile are the disparate individual works, many of them great and nearly every one provocative. The first gallery alone, under the rubric “American Icons,” is enough to credit the curatorial skills of Sidra Stich, the show's organizer. At the near end (in the Berkeley installation, at least), four “Flags” done by Jasper Johns between 1955 and 1965, each differently handled, gave off multiple sensations of grandeur and emblematic regret;