Change Details

With TSAN: ``` $ git checkout <previous commit hash> $ ninja &> before.log $ git checkout pr21598 $ ninja &> before.log $ grep "negative capability" before.log | wc -l 33 $ grep "negative capability" after.log | wc -l 0 ```

With TSAN: ``` $ git checkout <previous commit hash> $ ninja &> before.log $ git checkout pr21598 $ ninja &> after.log $ grep "negative capability" before.log | wc -l 33 $ grep "negative capability" after.log | wc -l 0 ```

With TSAN: ``` $ git checkout <previous commit hash> $ ninja &> before.log $ git checkout pr21598 $ ninja &> beforeafter.log $ grep "negative capability" before.log | wc -l 33 $ grep "negative capability" after.log | wc -l 0 ```