Disasm/asm doesn't round-trip for function with unused argument

[thegeez]

This doesn't round trip:

(asm (disasm 
    (fn [] 
       (def foo (fn [one two] one)) 
       (foo 100 200))))

This trips up this line in the bytecode verifier about slotcounts:

janet/src/core/bytecode.c

Line 409 in 6032a6d

if (maxslot > sc) return 2;

This example does work when foo returns two instead of one:

(asm (disasm 
    (fn [] 
       (def foo (fn [one two] two)) 
       (foo 100 200))))

[bakpakin]

Fixed in 9e6abbf