* Some more updates to PHP testing infrastructure (#8576)
* WIP.
* Added build config for all of the tests.
* Use ../src/protoc if it is available, for cases where Bazel isn't available.
* Added test_php.sh.
* Fix for the broken macOS tests.
* Move all jobs to use php80 instead of lots of separate jobs.
* Only pass -t flag if we are running in a terminal.
* Updated php_all job to use new Docker stuff.
* Fixed PHP memory leaks and arginfo errors (#8614)
* Fixed a bunch of incorrect arginfo and a few incorrect error messages.
* Passes mem check test with no leaks!
* WIP.
* Fix build warning that was causing Bazel build to fail.
* Added compatibility code for PHP <8.0.
* Added test_valgrind target and made tests Valgrind-clean.
* Updated Valgrind test to fail if memory leaks are detected.
* Removed intermediate shell script so commands are easier to cut, paste, and modify.
* Passing all Valgrind tests!
* Hoist addref into ObjCache_Get().
* Removed special case of map descriptors by keying object map on upb_msgdef.
* Removed all remaining RETURN_ZVAL() macros.
* Removed all explicit reference add/del operations.
* Added REFCOUNTING.md to Makefile.am.
* Updated upb version and fixed PHP to not get unset message field. (#8621)
* Updated upb version and fixed PHP to not get unset message field.
* Updated changelog.
* Fixed preproc test to handle old versions of Clang withot __has_attribute().
* A second try at fixing __has_attribute().
* Copy __has_attribute() fix to cc file also.
* Updated failure list for PHP for fixed test.
* Updated version of upb for Ruby (#8624)
* Updated upb.
* Preserve legacy behavior for unset messages.
* Updated failure list.
* Updated CHANGES.txt.
* Added erroneously-deleted test file.
* Fixed condition on compatibility code.
* Re-introduced deleted file again, and fixed Rakefile to not delete it.
* Fix generation of test protos.
* Updated upb version and fixed PHP to not get unset message field.
* Updated changelog.
* Fixed preproc test to handle old versions of Clang withot __has_attribute().
* A second try at fixing __has_attribute().
* Copy __has_attribute() fix to cc file also.
* Updated failure list for PHP for fixed test.
