Thank you for this, it does shed some light on these warnings.  So it
complains that if I declare an array the way I do and then, somewhere
else, I attempt to access the element at index NS_QUERY_HOOKS_COUNT
(which I never do, but Coverity does not know that), it will be
out-of-bounds?

If that is the case, I would just size the arrays using the original
enum value (NS_QUERY_HOOKS_COUNT) + 1, i.e. without renaming the last
enum value.