doesn't work for me, maybe by "modern" you mean a current Chrome or Firefox.
I tested it with QTweb, Chrome 43 and Opera (Presto), certainly not the most "mainstream" or "popular" or "latest" browsers around, still I find no real reason why the thingy shouldn't work with them.
Basically the first two actual instructions are not parsed correctly.
In Opera (12.15) I have three errors:
Syntax error at line 10 while loading: expected expression, got '>'
var to16 = (n, l) => {
-------------------^ Linked script compilation helpers.js
Syntax error at line 38 while loading: invalid character after numeric literal: 'b'.
n = b & 0b1111;
-------------^ Linked script compilation disassembler.js
Syntax error at line 2 while loading: expected expression, got '>'
hello.onclick = e => {
-------------------^ Linked script compilation demos.js
