Ran 'git cl format' over repo, found some nits

Change-Id: I5774e4cfc8a570522ac6533d69b5b87f7e5e0b6c
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/31081
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: dan sinclair <dsinclair@chromium.org>

src/validator_impl.cc

@@ -12,9 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <cassert>
 #include "src/validator_impl.h"
+
+#include <cassert>
 #include <unordered_set>
+
 #include "src/ast/call_statement.h"
 #include "src/ast/function.h"
 #include "src/ast/int_literal.h"