GDScript: Allow using local constants as types

[dalexeev]

• Closes Can't use local constant as type #80960.

In master you can only use member constants as types. Now it's possible:

enum MyEnum {A, B, C}

func _ready() -> void:
    const X = preload("1.gd")
    const Y = MyEnum
    var x: X
    var y: Y

I recommend hide whitespace changes for the review, since I increased the indentation level in a large block.

[adamscott]

@dalexeev Is it cherry-pickable?

[dalexeev]

@adamscott I think yes, with a small change in the parser from #79880 (add the IdentifierNode::suite property). However, I think it's more of an inconvenience than a significant limitation (it's easy to workaround by using member constant instead of local constant). In addition, we regularly publish 4.2 dev snapshots. But if production team thinks it's important enough for a cherry-pick, then I don't mind.

[adamscott]

This seems nice! Let's test it out.

[YuriSizov]

Thanks!