Issue Description:

I cannot use the IN operator on strings:
Results in a Bad type on operand stack Error

What happens:

[INITIALIZATION][CLIENT][ERROR] [crafttweaker]: Error executing {[0:crafttweaker]: test2.zs}: Bad type on operand stack
Exception Details:
Location:
Test2.script()V @19: invokestatic
Reason:
Type integer (current frame, stack[1]) is not assignable to 'java/lang/String'

What you expected to happen:

Being able to use in on strings.
See https://crafttweaker.readthedocs.io/en/latest/#Vanilla/Variable_Types/Basic_Variables_Functions/

Script used (Please Pastebin or gist your script, posting an unpasted or ungist'd script will automatically close this issue):

https://gist.github.com/Guinaro/ba2329a3806fc6abc952e7c5efcb42c5

Minetweaker.log file (Please Pastebin or gist your file, posting an unpasted or ungist'd file will automatically close this issue):

https://gist.github.com/Guinaro/fa3376fe1478e7fe0d2933aad6230940

Affected Versions (Do not use "latest"):

• Minecraft: 1.12.2
• Forge: 14.23.2.2618
• Crafttweaker: 1.12-4.1.5

Your most recent log file where the issue was present:

https://gist.github.com/Guinaro/a81380f6bb9215e2ff66e24508928936

Fixed in ZenScript :)