Three of these runtimes are based on upb, and the fourth is based on the Java runtime. Both of these already have editions support, so this was mostly just a matter of:
- Advertising support to allow editions codegen
- Stripping features from the runtime options
- Hooking up conformance tests
- Adding some lightweight editions tests
There are also a few minor orthogonal fixes included here:
- Ruby's upb hack for treating all enums as open enums needed tweaking
- The `enable_editions` flag is no longer needed in our internal proto rules
PiperOrigin-RevId: 616256211
Mike Kruskal