Where is HAVE_SQLITE3_COLUMN_DATABASE_NAME defined? #460

I am trying to understand how the gem determines whether or not to include the database_name method in the definition of the Statement class.

The code references a HAVE_SQLITE3_COLUMN_DATABASE_NAME constant in two places:

And the tests say that this method is defined or not depending on how SQLite was compiled:

But, a search of the SQLite source doesn't return any use of this constant. And the docs say that the compilation flag used is SQLITE_ENABLE_COLUMN_METADATA.

So, how and where is the HAVE_SQLITE3_COLUMN_DATABASE_NAME constant set and how does that relate to the SQLITE_ENABLE_COLUMN_METADATA compilation flag?