HHH-18976 Avoid usage of Array.newInstance

[yrodiere]

https://hibernate.atlassian.net/browse/HHH-18976

Two things in here:

1. Sets up forbiddenapis to forbid usage of Array.newInstance (and util methods known to use it) by default. This is mostly as a heads-up to not use it "just because", since the check can be bypassed if necessary by annotating the method with @AllowReflection.
2. Reworks a few implementations to avoid usage of Array.newInstance. E.g.:
   • use array.clone() where relevant (i.e. when we want the same array type with the same length).
   • don't use Array.newInstance just to retrieve the Class of an array type -- since we ultimately just look use that Class to look up a descriptor in a registry.
   • use new Object[...] instead where possible (e.g. when the array ends up being used internally only).

This should get rid of most problematic uses of reflection when compiling to native binaries (see Jira issue).
There are still a few uses of Array.newInstance but as far as I can see they are completely justified and cannot easily be worked around: array mapping, JSON/XML serialization, instantiation of query result types, ...

[yrodiere]

Hey @sebersole @beikov, this might be of interest to you. I'm still waiting for the full CI run -- I personally only ran tests in a few relevant test packages. But assuming tests pass, I think merging this would make HHH-16809 / #6815 mostly irrelevant... A JavaType#createArray method could still be useful in the future, but more for performance purposes (e.g. use primitive arrays) that would require more extensive changes.

EDIT: FWIW: HHH-18976...HHH-16809. It's unfinished, I didn't implement newArray (renamed from createArray) everywhere, but you can at least see where it would get used.

[yrodiere]

So I thought this, given the implementation of H2Dialect, meant arrays were in use for H2 as well:

hibernate-orm/hibernate-core/src/main/java/org/hibernate/persister/entity/AbstractEntityPersister.java

Line 859 in 0a2c229

protected MultiIdEntityLoader<Object> buildMultiIdLoader() {

But apparently they are not, so the successful tests I had locally were meaningless and I need to test on postgres specifically.

Back to the drawing board...

EDIT:

hibernate-orm/hibernate-core/src/main/java/org/hibernate/dialect/H2Dialect.java

Lines 199 to 203 in 928799d

	@Override
	public boolean useArrayForMultiValuedParameters() {
	// Performance is worse than the in-predicate version
	return false;
	}

-_-

[yrodiere]

Closing, will submit another PR with a more conservative solution.