WT uses a standard `flags` field across multiple structures that is implemented as a bitset. Each structure uses a set of sorted define statements.
It would be nice if there was a GDB pretty printer that additionally gave a string readable form with the `flag` member value. This would require the source file being present and checked out to the right version. That seems like a reasonable requirement because flag values can change between commits; having the proper file is necessary for a human to know what flags are set.