clang-format: Make braced list formatting more consistent.

clang-format: Make braced list formatting more consistent.

Before:
  Aaaa aaaaaaaaaaa{
      {
       a, // +1 indent weird.
       b, // trailing comma signals one per line.
      },  // trailing comma signals one per line.
  };

After:
  Aaaa aaaaaaaaaaa{
      {
          a, // better!?
          b, // trailing comma signals one per line.
      },     // trailing comma signals one per line.
  };

Interesting that this apparently was entirely untested :-(.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@230627 91177308-0d34-0410-b5e6-96231b3b80d8