Incompatible with latest bazel rolling release

[jpsim]

The toolchains defined in this ruleset no longer work as of the latest bazel rolling release (6.0.0-pre.20220630.1).

With bazelisk:

$ echo "6.0.0-pre.20220630.1" > .bazelversion
$ bazel build //toolchains:toolchain_java8 
Starting local Bazel server and connecting to it...
ERROR: /Users/jsimard/src/rules_java/toolchains/BUILD:212:27: no such target '@remote_java_tools//:java_compiler_jar': target 'java_compiler_jar' not declared in package '' defined by /private/var/tmp/_bazel_jsimard/95ec1fe9f24ed3702894a39337881861/external/remote_java_tools/BUILD and referenced by '//toolchains:toolchain_java8'
ERROR: /Users/jsimard/src/rules_java/toolchains/BUILD:212:27: no such target '@remote_java_tools//:jdk_compiler_jar': target 'jdk_compiler_jar' not declared in package '' defined by /private/var/tmp/_bazel_jsimard/95ec1fe9f24ed3702894a39337881861/external/remote_java_tools/BUILD and referenced by '//toolchains:toolchain_java8'
ERROR: Analysis of target '//toolchains:toolchain_java8' failed; build aborted: Analysis failed
INFO: Elapsed time: 2.661s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (6 packages loaded, 6 targets configured)

The previous release works just fine:

$ echo "6.0.0-pre.20220608.2" > .bazelversion
$ bazel build //toolchains:toolchain_java8 
INFO: Analyzed target //toolchains:toolchain_java8 (52 packages loaded, 809 targets configured).
INFO: Found 1 target...
Target //toolchains:toolchain_java8 up-to-date (nothing to build)
INFO: Elapsed time: 9.908s, Critical Path: 0.02s
INFO: 1 process: 1 internal.
INFO: Build completed successfully, 1 total action

It started failing as of this bazel commit: bazelbuild/bazel@8349a39

Which I believe is applying this change: bazelbuild/bazel@6ad6de9

If that's the case, it's my understanding that rules_java will need to stop using the java_compiler_jar and jdk_compiler_jar from remote_java_tools. Perhaps this could be done by vendoring these compiler jars in rules_java itself. I'll let maintainers decide the best way to handle this.

[comius]

Thanks for a great analysis!