Right now, symbolize_trace uses 'atos' with command line arguments. This is limited by maximum length for a command, which means we need to call 'atos' multiple times. It turns out that 'atos' is slow because it needs to load symbols from the dSYM, not b/c translating addresses to symbols is slow. Staring some more at the man page, we should be able to improve this by using a single instance of atos. Specifically, there are three ways to provide arguments:

     1.   A list of addresses at the end of the argument list.
     2.   Using the -f <address-input-file> argument to specify the path of an input file containing whitespace-separated numeric addresses.
     3.   If no addresses were directly specified, atos enters an interactive mode, reading addresses from stdin.

(2) seems like the easiest way to get all addresses symbolicated, and as long as the performance of that is fine, we might as well use it.