It seems like this class violates the usual protocol for initialization of javac components: a new binding computer seems to be returned each time the factory method is called (e.g. there is no instance field to which the singleton instance is saved):

https://github.com/openjdk/jdk/blob/22e17c29a2a4eb546fae4c01ae435283654e3bb3/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/MatchBindingsComputer.java#L50