This PR does the following:
* Special-case descriptor.proto to allow for codegen despite being proto2
* Fix a pre-existing bug that gets exercised now during descriptor builds
* Expand test coverage of conformance tests, and fix pre-existing issues
* Properly hook up gencode to staleness infrastructure for automated regen
Closes#18610
COPYBARA_INTEGRATE_REVIEW=https://github.com/protocolbuffers/protobuf/pull/18610 from protocolbuffers:php-regen 773a1bf01a
PiperOrigin-RevId: 682477438
This is the second attempt to fix our Git history. This should allow
"git blame" to work correctly in the upb/ directory even though our
automation unexpectedly blew away that directory.
This renaming is something we have been planning on doing, and I would
like to do it now because I'm getting ready to rely on this
staleness_test() macro from the main protobuf repo.
Mike Kruskal
Adam Cozzette
Protobuf Team Bot
Joshua Haberman