var log = []
textNamesToGroups( activeDocument )
alert( log.join('\n\n') )



function textNamesToGroups( doc ) { try {
  var lyrs = deepArtLayers( doc.layers )
  log.push( 'lyrs:\t' + lyrs.join( '\n\t' ))

  for( var i=0; i<lyrs.length; i++ ) { try {
    var lyr = lyrs[i]
    if( lyr.kind == LayerKind.TEXT && lyr.parent.typename == 'LayerSet' ) {
      log.push( 'layerSet: '+ lyr.parent.name +' --> '+ lyr.name )
      lyr.parent.name = lyr.name
    }
  } catch(e) { log.push(e) } }

} catch(e) { log.push( 'textNamesToGroups '+ e ) } }



function deepArtLayers( lyrs ) { try {
  var deepArtLyrs = []
  for( var i=0; i<lyrs.length; i++ ) {
    var lyr = lyrs[i]
    if( lyr.typename == 'LayerSet' ) {
      deepArtLyrs = deepArtLyrs.concat( deepArtLayers( lyr.layers ) ) }
    else deepArtLyrs.push( lyr )
  }
  return deepArtLyrs
} catch(e) { log.push( 'deepArtLayers '+ e ) } }