where the abortable table function abortableTableAlt is described at the bottom of this answerthis answer. The process was time and memory-consuming, so I saved the result to a file, available from this gist. The result has this format:
You can import the file from the mentioned gist, and I'd recommend to use Dispatch to speed up the rule application. Alternatively, you can use Save to attach these rules to whatever function (symbol) you want. As was suggested in another answer, this can be combined with some tool to extract dependencies, which would give you a list of system symbols used in your code. One such tool was developed David Wagner way back in 1996 and desribed in his article in the Mathematica Journal. I developed a similar tool herehere, but it is a work in progress and contains some bugs as of now.