<https://www.sqlite.org/c3ref/enable_shared_cache.html> appears to indicate that the function is deprecated on OSX 10.7 and iOS 5.0, but looking at the latest sources on sqlite.org that's not the case, the warning in the documentation appears to be for the version of SQLite that Apple ships with their systems.

Because of this I'm against merging this patch as is because it also affects anyone building using the upstream version of SQLite instead of the version shipped with OSX.

I'm -0 on suppressing the warning other ways, either by detecting that the build uses Apple's build of SQLite or by using pragma's to disable deprecation warnings for this functions.