Even if feature about serialization (from GraalVM 21.0 ) is proposed, small change could make it work even now

[JiriOndrusek]

Description
There is an issue about Better DevExp for serialization feature support as of GraalVM 2 (#14530)

But it is possible to make serialization work only by removing substitution, which cuts off serialization - see 214e05c

Implementation ideas
I've tested camel-quarkus nitrite extension, which uses java serialization.

With provided serialization mapping (JiriOndrusek/camel-quarkus@04134ef#diff-e008186a29d7dc393c8bc2c05a5303d14d3f13050f7f48dc08b27d50edaf68f9R1) and removed substitution https://github.com/quarkusio/quarkus/blob/master/core/runtime/src/main/java/io/quarkus/runtime/graal/JavaIOSubstitutions.java, serialization works. (my test could be used as reproducer, use this commit JiriOndrusek/camel-quarkus@04134ef and execute by mvn clean verify -Pnative -f integration-tests/nitrite)

I'd like to suggest to remove substitution https://github.com/quarkusio/quarkus/blob/master/core/runtime/src/main/java/io/quarkus/runtime/graal/JavaIOSubstitutions.java. (if it makes sense)

[gsmet]

@JiriOndrusek if CI is OK with it, I'm OK too.

[JiriOndrusek]

@gsmet Sorry, I didn't understand correctly. I'll try to create PR and see whether CI is ok. I've tested only my usecase.