Saxon

The source and target compatibility flags were accidentally set to "11" not "1.8" in the build scripts.

However, I assume that only fixes the build issue and it would still fail on Java 8 because of the Java 9 dependency...

I have moved all the dependencies on java.lang.ref.Cleaner into one place (CleanerProxy.java) which is designed to have fallback behaviour if the Cleaner class is not available. The fallback action is not yet tested.

Also noted, there are also "soft" Java 9 dependencies in JavaPlatform.java, with fallback action for Java 8.

I have added a note on the website (https://www.saxonica.com/products/latest.xml#saxonJ12) where we mention Java versions, so that it now says:

SaxonJ 12 is built and tested using Java 11, but should still be usable with Java 8 or later. (However, due to bug #5824, note that SaxonJ 12.0 does not run on Java 8.)

I decided against adding this note in the documentation (because it's a code bug and we don't generally update the documentation to highlight code bugs). But let me know if you think I should. (The relevant documentation pages are: about/gettingstarted/gettingstartedjava, about/installationjava/prerequisites, changes/installation.)