New file created in Xcode 9.3, .xcworkspace/xcshareddata/IDEWorkspaceChecks.plist should it be committed?

From 9.3 release notes, it sounds like you’d want to commit.

Xcode 9.3 adds a new IDEWorkspaceChecks.plist file to a workspace’s
shared data, to store the state of necessary workspace checks.
Committing this file to source control will prevent unnecessary
rerunning of those checks for each user opening the workspace.

Source