Registry DSL does not check types of registered items on compile

[waterlilly-lilly]

The Registry DSL does not properly check the type of registry items on compile time. For example, a Block can be registered to the Item registry without a compile time error, only crashing at runtime with a potentially confusing exception.
Test code:

object ExampleMod : ModInitializer {
    val TEST_BLOCK: Block = Block(QuiltBlockSettings.of(Material.STONE)
    override fun onInitialize(mod: ModContainer) {
        Registries.ITEM {
            TEST_BLOCK withId Identifier("example_mod:test_block")
        }
    }
}

This code will compile, but on runtime the game will crash with the error java.lang.IllegalStateException: Some intrusive holders were not registered: [Reference{null=Block{minecraft:air}}], which may be confusing and does not reveal the true cause of the issue.

[Cypher121]

From a cursory look, the issue seems to be that there's a fallback function that matches withId in this example

Registry.invoke call on line 4 of the example creates a RegistryAction<Item> scope and its withId method (this one) will only accept subtypes of item.

Since it doesn't match though, the compiler finds a function that does: this one, one that doesn't require a RegistryAction scope and just makes an object.

So the error here isn't that it's registered into the wrong registry (which would most assuredly give a ClassCast somewhere), it ends up not being registered anywhere.

Would help to add CheckReturnValue to the loose withId, but ideally it should be renamed or moved to a different context.