While `go` is intended to be called with either one int arugment or
one string and one int argument, Director accepts multiple int args.
In this case, it treats the first argument as an integer and silently
discards the rest. Before this branch, ScummVM would always treat two
arguments as being the movie + frame case and throw a typecheck error
for the first argument. This fixes it by checking the type of the first
arg and discarding the rest, matching Director's behaviour.
This was seen on the title screen of Wallobee Jack: The Thai Sun Adventure,
which calls it like so: `go (the frame) 0`
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