clang-format: Don't indent relative to unary operators.

It seems like most people see unary operators more like part of the
subsequent identifier and find relative indentation odd.

Before:
  aaaaaaaaaa(!aaaaaaaaaa( // break
                  aaaaa));
After:
  aaaaaaaaaa(!aaaaaaaaaa( // break
                 aaaaa));

llvm-svn: 200840