Refine range check in JavaCompliance.

[oraluben]

This PR updates JavaCompliance, including:

1. Better JavaCompliance.__contains__. It now checks every parts of JavaCompliance instances, rather than only the high and low bounds. mx.JavaCompliance("16") in mx.JavaCompliance("11..15,17") now returns False as expected;
2. Fix incorrect version check when having requiresConcealed with java compliance specified, this also helps to port Graal to JDK 19.

[oraluben]

@dougxc This is the ready-to-review part of #263, with range tests included.

[dougxc]

@gilles-duboscq could you please help review this as well.

[dougxc]

This is a backwards incompatible change. That is, projects that depending on JDKConfig._is_loom will break. Yes, I know that this is a "private" field but I see we have some internal test that use it unfortunately. You may even remember writing them ;-)
I've opened GR-39470 internally to address this but for now, we need to preserve this field and ensure it is initialized properly.

[oraluben]

You may even remember writing them ;-)

Now I do 🤣

Anyways, the Loom cleanup is not so urgent at the moment, but I do hope the java compliance changes to be merged if you think it's ok, I'll remove the loom changes from this PR.

[gilles-duboscq]

I agree we need to keep the loom flags and behaviors, the other changes look good.

[dougxc]

Resolved by 49f40cad895bc2603407f15057b66d0d6d8e1baa.