Avoid breaking non-trailing block comments.

Motivating example:
// column limit ------------------->
void ffffffffffff(int aaaaaa /* test */);

Formatting before the patch:
void ffffffffffff(int aaaaaa /* test
                              */);

Formatting after the patch:
void
ffffffffffff(int aaaaaa /* test */);



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186471 91177308-0d34-0410-b5e6-96231b3b80d8