[wasm] `test-main.js` needs an unhandled exception handler

[radical]

When running tests with xharness on browser, we are not able to get the traces for uncaught exceptions. A handler for that can print the trace which can be usable by anyone looking at test logs.

[11:20:03] info: Starting:    System.Runtime.Tests.dll
[11:21:00] fail: [out of order message from the browser]: http://127.0.0.1:49197/dotnet.js 1880:6 Uncaught
[11:21:00] fail: [out of order message from the browser]: http://127.0.0.1:49197/dotnet.js 1880:6 Uncaught
[11:21:00] fail: [out of order message from the browser]: http://127.0.0.1:49197/dotnet.js 1880:6 Uncaught
[11:34:33] fail: Tests timed out. Killing driver service pid 7840
[11:34:33] fail: Application has finished with exit code TIMED_OUT but 0 was expected

Also, note the timings above. xharness continues to wait for 13mins after the uncaught exception, because the app did not signal that it had crashed.

Tagging subscribers to 'arch-wasm': @lewing
See info in area-owners.md if you want to be subscribed.

Issue Details

---

When running tests with xharness on browser, we are not able to get the traces for uncaught exceptions. A handler for that can print the trace which can be usable by anyone looking at test logs.

[11:20:03] info: Starting:    System.Runtime.Tests.dll
[11:21:00] fail: [out of order message from the browser]: http://127.0.0.1:49197/dotnet.js 1880:6 Uncaught
[11:21:00] fail: [out of order message from the browser]: http://127.0.0.1:49197/dotnet.js 1880:6 Uncaught
[11:21:00] fail: [out of order message from the browser]: http://127.0.0.1:49197/dotnet.js 1880:6 Uncaught
[11:34:33] fail: Tests timed out. Killing driver service pid 7840
[11:34:33] fail: Application has finished with exit code TIMED_OUT but 0 was expected

Also, note the timings above. xharness continues to wait for 13mins after the uncaught exception, because the app did not signal that it had crashed.

Author:	radical
Assignees:	pavelsavara
Labels:	arch-wasm, test-enhancement, area-VM-meta-mono
Milestone:	7.0.0

[pavelsavara]

Should xharness kill the test on any unhanded exception ?

[radical]

The runtime should print the details for the error, and then exit, which would trigger xharness to kill the browser process.