I went through gcc bugzilla and counted PRs that are fixed by
gcjx. I came up with 72, though a few of those are maybes. Chances
are, if you have found a front end bug in gcj, it is already fixed in
gcjx.

This weekend I also changed gcjx to optionally run the bytecode
verifier on the bytecode it creates, before writing it out. This
caught a couple of code generation bugs (and a funny buglet in the
verifier — it failed to special-case Object.<init>).