Rust: Use doublyBoundedFastTC in TraitIsVisible

[hvitved]

No description provided.

[Copilot]

Pull Request Overview

This PR refactors the TraitIsVisible module to use the more efficient doublyBoundedFastTC predicate instead of a custom recursive lookup implementation. The change improves performance by leveraging CodeQL's optimized transitive closure computation for determining trait visibility.

Key Changes

• Replaced recursive traitLookup predicate with a graph-based approach using doublyBoundedFastTC
• Introduced a new type system (TNode) to represent the nodes in the visibility graph
• Simplified the main traitIsVisible predicate logic

[Copilot]

The getASuccessor call is missing the required name parameter. Based on the context, this should be t1 = i2.getASuccessor(_, _) where the first underscore represents the name parameter.

Suggested change

	exists(Trait t1, ItemNode i2 |
	n1 = TTrait(t1) and
	n2 = TItemNode(i2) and
	t1 = i2.getASuccessor(_, _)
	exists(Trait t1, ItemNode i2, string name |
	n1 = TTrait(t1) and
	n2 = TItemNode(i2) and
	t1 = i2.getASuccessor(name, _)

[Copilot]

The direction of the relationship appears reversed. Based on the original traitLookup logic, this should be i2 = getOuterScope(i1) to represent moving from an inner scope to an outer scope.

Suggested change

	i1 = getOuterScope(i2)
	i2 = getOuterScope(i1)