lang: Remove unneeded object_create check

lang: Use integers for private data to avoid casting void ...

This adds a table for class to bytecode mapping which isn't ideal,
but it's arguably a good thing that's probably needed in the future.

lang: Clean up one-line if statements

lang: Add multiply and divide and rational loop test

lang: Use mpq functions for rational math

lang: Allow creating rationals from an mpq value

lang: Change rational_value to rational_integer

lang: CAnonicalize rationals

lang: Rename number to rational