ENVIRONMENT RETURN-STACK-CELLS
* ENVIRONMENT RETURN-STACK-CELLS ( -- value )

the number of cells allocated for the return stack of forth.
it can be set with a startup option to match different needs
of applications. (like ENVIRONMENT STACK-CELLS) unless
the return-stack is made in hardware (like on some special
forth CPUs) or aliased with the return-stack provided by
the hosting operating system for the forth process thread.

ENVIRONMENT core ordinary primitive