[clang-format] Avoid considering include directive as a template closer.

This fixes a bug [[ http://llvm.org/PR48891 | PR48891 ]] introduced in D93839 where:
```
#include <stdint.h>
namespace rep {}
```
got formatted as
```
#include <stdint.h>
namespace rep {
}
```

Reviewed By: MyDeveloperDay, leonardchan

Differential Revision: https://reviews.llvm.org/D95479