This reverts commit 082a47d8944da242993bf28980b07f2c8c3df4a6. `ToolSubst` should only be used explicitely for passing `extra_args`.
This reverts commit 082a47d8944da242993bf28980b07f2c8c3df4a6. `ToolSubst` should only be used explicitely for passing `extra_args`.