Feat: add now can add two full strings
Fix: it2 would have different working for emit eof
Fix: eq and lt would return bools on it0 and it1
Fix: Functions always return something (there is no such
thing as an empty type).
Fix: Return value from main is now always ignored.
Fix: Output from check is same on all iterations
With the new check function, this helper method doesn't make
much sense to put in the standard library.
To replicate the same result, we do need to expose the current
line number; adding column number is a nice bonus.
Also; made it a bit clearer when a check failes in it2.
Also; the builtincheckfalse was not working.
Also; separated out the test input file to have more data.