Prior to jsoncpp commit `126bdc2b05` (Reject extra chars if strictRoot,
2016-08-21, 1.7.5~2), it did not diagnose trailing characters in the
input after a JSON value. Teach our corresponding test case to tolerate
the old behavior.
Add support for client-owned *stateful* query files. These allow
clients to request a list of versions of each object kind and get only
the first-listed version that CMake recognizes. Since clients own their
stateful query files they can mutate them over time. As a client
installation is updated it may update the queries that it writes to
build trees to get newer object versions without paying the cost of
continuing to generate older versions.
Issue: #18398