A quick and dirty PHP script to convert Dxbx symbol cache files (.sym) to IDC scripts for IDA Pro.
php -f sym2idc.php [infile] > [outfile]
In IDA Pro, go to File => IDC Script and Select the output file of this tool
php -f sym2idc.php "FFFE0000_4C0590E3_Xbox OnlineDash.sym" > "FFFE0000_4C0590E3_Xbox OnlineDash.idc"
An example input and output is included in this repository.