Timeout001 fails non-deterministically on Windows
```patch
--- /dev/null 2019-08-06 16:29:29.000000000 +0000
+++ libraries/base/tests/System/Timeout001.run/Timeout001.run.stderr.normalised 2019-08-06 16:29:28.989811300 +0000
@@ -0,0 +1 @@
+onIOComplete: failed to grab table semaphore, dropping request 0x15d7
```
This will likely be fixed with !1224.
issue