/** Return loop depth of node.
*
* Returns the loop depth of n in the control flow. I.e., we
* go from the node to the block to the loop the block is in,
* and return its depth. */
/** Return loop depth of node.
*
* Returns the loop depth of n in the control flow. I.e., we
* go from the node to the block to the loop the block is in,
* and return its depth. */