code: private Node tryOptimizeNameDeclaration(Node subtree) {
      checkState(NodeUtil.isNameDeclaration(subtree));
      Node left = subtree.getFirstChild();
      if (left.isDestructuringLhs() && left.hasTwoChildren()) {
        Node pattern = left.getFirstChild();
        if (!pattern.hasChildren()) {
          // `var [] = foo();` becomes `foo();`
          Node value = left.getSecondChild();
          subtree.replaceWith(IR.exprResult(value.detach()).srcref(value));
          reportChangeToEnclosingScope(value);
        }
      }
      return subtree;
    }
docs: Try removing identity assignments and empty destructuring pattern assignments
  
  @return the replacement node, if changed, or the original if not