This is based on this issue #423.

This is just a draft but I was able to run the example that @eliaslfox provided in the issue.

for example:

CL-USER> (in-package :coalton-user)
#<COMMON-LISP:PACKAGE "COALTON-USER">
COALTON-USER> (coalton-toplevel
		(declare f (IFix -> String))
		(define (f x)
		  (match x
		    (5 "five")
		    (_ "not five"))))
			 
; No value
COALTON-USER> (coalton (f 5))
"five"

Some things I am thinking about is if theres a better way to distinguish the positive fixnums from integers.

I am aware that by doing the length of the integer. but I am still thinking how to distinguish better.

(integer-length most-positive-fixnum)