clang-format: Improve ObjC variadic and binary expression parameters.

Before:
  [self aaaaaaaaaaaaaaa:aaaaaaaaaaaaaaa | aaaaaaaaaaaaaaa | aaaaaaaaaaaaaaa |
                           aaaaaaaaaaaaaaa | aaaaaaaaaaaaaaa | aaaaaaaaaaaaaaa |
                           aaaaaaaaaaaaaaa | aaaaaaaaaaaaaaa];
  [self aaaaaaaaaaaaaaa:aaaaaaaaaaaaaaa,
      aaaaaaaaaaaaaaa, aaaaaaaaaaaaaaa, aaaaaaaaaaaaaaa, aaaaaaaaaaaaaaa,
      aaaaaaaaaaaaaaa, aaaaaaaaaaaaaaa, aaaaaaaaaaaaaaa];

After:
  [self aaaaaaaaaaaaaaa:aaaaaaaaaaaaaaa | aaaaaaaaaaaaaaa | aaaaaaaaaaaaaaa |
                        aaaaaaaaaaaaaaa | aaaaaaaaaaaaaaa | aaaaaaaaaaaaaaa |
                        aaaaaaaaaaaaaaa | aaaaaaaaaaaaaaa];
  [self aaaaaaaaaaaaaaa:aaaaaaaaaaaaaaa, aaaaaaaaaaaaaaa, aaaaaaaaaaaaaaa,
                        aaaaaaaaaaaaaaa, aaaaaaaaaaaaaaa, aaaaaaaaaaaaaaa,
                        aaaaaaaaaaaaaaa, aaaaaaaaaaaaaaa];

This addresses llvm.org/PR15349 and llvm.org/PR16185.