Static analyzer does not handle multiple trailing closures

The SyntaxTree.FunctionCall model only captures a single trailingClosure. Swift's multiple trailing closure syntax (additional trailing closures) is silently dropped during syntax tree building (SyntaxTreeBuilder.swift, FunctionCallExprSyntax.syntaxDescription).

This means:

• Closures passed as additional trailing closures are invisible to the static analyzer
• For immediate closure support, only the first trailing closure is checked — additional closure arguments are not analyzed

Example

UIView.animate(withDuration: 0.3) {
  // animations — this is the trailing closure, currently captured
} completion: { finished in
  // completion — this is an additional trailing closure, currently dropped
}

Steps

1. Extend SyntaxTree.FunctionCall to model additional trailing closures
2. Update FunctionCallExprSyntax.syntaxDescription to populate them
3. Update SemaTreeBuilder.visit(functionCall:) to visit additional trailing closures
4. Consider which closures should inherit scope in Context.isImmediateClosureCall

Start with SyntaxTreeBuilder.swift, FunctionCallExprSyntax.syntaxDescription, and SemaTreeBuilder.visit(functionCall:), then trace Context.isImmediateClosureCall for the scope question. Use the UIView.animate example to verify that both the trailing and additional trailing closures are represented and analyzed, with the intended scope behavior confirmed.