Revert "[syscall_model] Update the interface for accessing the arguments to the syscall."
Revert "[syscall_model] Update the interface for accessing the arguments to the syscall."

This reverts commit 6ebe774cb9b305aaffe52e2140010dc85e595a17.

nkawahara/Graphite,8l/Graphite,fhijaz/Graphite,nkawahara/Graphite,victorisildur/Graphite,mit-carbon/Graphite,victorisildur/Graphite,nkawahara/Graphite,8l/Graphite,fhijaz/Graphite,mit-carbon/Graphite-Cycle-Level,mit-carbon/Graphite-Cycle-Level,fhijaz/Graphite,8l/Graphite,8l/Graphite,mit-carbon/Graphite-Cycle-Level,victorisildur/Graphite,victorisildur/Graphite,fhijaz/Graphite,mit-carbon/Graphite-Cycle-Level,mit-carbon/Graphite,mit-carbon/Graphite,mit-carbon/Graphite,nkawahara/Graphite