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..)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190854 91177308-0d34-0410-b5e6-96231b3b80d8