Bug 259289

The `run-jsc-stress-tests` script is intended to run some Wasm JetStream2 tests via the `wasm-cli.js` script.

Right now, it appears that this was unintentionally broken. For example, see the following commandline example:

```
$ time Tools/Scripts/run-jsc-stress-tests --jsc ~/WebKit/WebKitBuild/Release/bin/jsc -c 32 JSTests/wasm.yaml --filter JetStream2

<test printout here>

11/11            

real    0m3.649s
user    0m1.583s
sys     0m2.357s
```

This runtime is suspiciously short for running perf tests. If you edit `wasm-cli.js` to replace the `console.log` with `print`
instead of a no-op function, it prints the following instead:

```
wasm.yaml/PerformanceTests/JetStream2/wasm-cli.js.wasm-air: Starting JetStream2
wasm.yaml/PerformanceTests/JetStream2/wasm-cli.js.wasm-air: Running tsf-wasm:
wasm.yaml/PerformanceTests/JetStream2/wasm-cli.js.wasm-air: Error in runCode:  ReferenceError: Can't find variable: isD8
```

This shows that the script is broken and exiting before running the tests. There's a simple patch that should make this work again which I'll post later.