Copy over runfiles library from Bazel

[fmeum]

The runfiles library can be maintained independently of Bazel releases and bazel_tools can refer to it via an alias.

Also set flags to build and test with a hermetic JDK 8 to ensure compatibility with that version.

[fmeum]

@hvadehra @meteorcloudy I just realized that we could also move this over and delete it from bazel_tools. What do you think? We could fix bazelbuild/bazel#24150 here.

[comius]

The move sounds fine to me. I'll let @hvadehra do the review.

[fzakaria]

@hvadehra @meteorcloudy I just realized that we could also move this over and delete it from bazel_tools. What do you think? We could fix bazelbuild/bazel#24150 here.

I included the fix in bazelbuild/bazel#24161
It doesn't have any unit tests since there seem to be none to add.
A further contribution may be to include https://github.com/google/compile-testing at some point

[fmeum]

Stacked on #238

No longer stacked

[fmeum]

@hvadehra This is ready for review now, CI is green.

[fmeum]

@hvadehra Friendly ping

[hvadehra]

Sorry about the delay.

[fmeum]

@Wyverald http_jar in rules_java doesn't work with Bazel 6 as it loads cache.bzl, which isn't available in that Bazel version.

[Wyverald]

@Wyverald http_jar in rules_java doesn't work with Bazel 6 as it loads cache.bzl, which isn't available in that Bazel version.

I'm aware of this (decided not to try to fix it since it's too much work). Is it blocking you?

[fmeum]

If you are aware of this it's fine, it just means that rules_java can't use it yet.

[hvadehra]

@fmeum This is causing a few issues on import, could you please change the newly added BUILD files to BUILD.bazel?

[fmeum]

@hvadehra Done

[fmeum]

@hvadehra Could you cut a new release so that this can be integrated into bazelbuild/bazel#24219?

[hvadehra]

Done: bazelbuild/bazel-central-registry#3213