This Pull Request offers a basic VM fuzzer which relies on implied oracles (namely, "does it crash or timeout?").
It changes the following:
- Adds an insns_remaining field to Context, denoting the number of instructions remaining to execute (only available when fuzzing)
- Adds a JsNativeError variant, denoting when the number of instructions has been exceeded (only available when fuzzing)
- Adds a VM fuzzer which looks for cases where Boa may crash on an input
This offers no guarantees about correctness, only assertion violations. Depends on #2400.
Any issues I raise in association with this fuzzer will link back to this fuzzer.
You may run the fuzzer using the following commands:
```bash
$ cd boa_engine
$ cargo +nightly fuzz run -s none vm-implied
```
Co-authored-by: Addison Crump <addison.crump@cispa.de>
Addison Crump