Fix and refactor splat argument parsing.
Fix and refactor splat argument parsing.

Maxwell-Alexius/goby,st0012/Rooby,hachi8833/goby,Maxwell-Alexius/goby,hachi8833/goby,hachi8833/goby,st0012/Rooby,goby-lang/goby,goby-lang/goby,goby-lang/goby,Maxwell-Alexius/goby