Fix line-breaking problem caused by comment.

Before, clang-format would not find a solution for formatting:
if ((aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa ||
     bbbbbbbbbbbbbbbbbb) && // aaaaaaaaaaaaaaaa
    cccccc) {
}

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183096 91177308-0d34-0410-b5e6-96231b3b80d8