clang-format: Don't split a >>-operator.

Before (with column limit 60):
  aaaaaaaaaaaaaaaaaaaaaaaaaaaa(aaaaaaaaaaaaaaaaaaaaaaaaaaaaa >
      > aaaaa);

After:
  aaaaaaaaaaaaaaaaaaaaaaaaaaaa(
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaa >> aaaaa);

(Not sure how that could have stayed in that long without being
detected..)

llvm-svn: 190854