feat: add configurable interpreter step limit for moc.js

[rvanasa]

Adds an optional deterministic step limit to the moc.js interpreter.

This feature will protect users from accidentally crashing the browser with a code snippet such as while true {} now that we are using a trampoline (#3541), so I suppose this is a nice problem to have.

[github-actions]

Comparing from e602092 to 81a1932:
The produced WebAssembly code seems to be completely unchanged.

[crusso]

If needs must.

Does the browser hang indefinitely or offer a cancel script prompt eventually?

If the former, I wonder why a while (true) { }diverges, but the similar bounded loop on the trampoline PR stack-overflowed, There, decrementing a counter for 163840 steps exits with stack overflow (but 16384 is ok).

[rvanasa]

Does the browser hang indefinitely or offer a cancel script prompt eventually?

Browser hangs indefinitely and requires reopening the tab.

I wonder why a while (true) { } diverges, but the similar bounded loop on the trampoline PR stack-overflowed

Yeah, same. I'll try to reverse-engineer the stack trace in case there's a way we can mitigate whatever is going on here.

[crusso]

Yeah, I actually didn't think to look a the developer tool pane to figure out why the overflow was happening. It could be that we are missing some extra trampolines in other interpreter functions, but I experimented with adding some and didn't get anywhere (or maybe didn't refresh the browser hard enough).