Ninja: metadata clean-on-regenerate broken on Windows

The change in !3316 (merged) for #15830 (closed) does not work on Windows with Ninja 1.10 when running ninja re-runs CMake internally. The outer ninja holds the log files open so the ninja -t * tools fail with:

ninja: error: failed recompaction: Permission denied

Edited Jan 27, 2020 by Brad King

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information