Intent to prototype and ship: self.reportError()

[Tom Schuster]

Summary: This allows libraries to emulate the behavior of throwing
exceptions in an event listener (triggers self.onerror). Aka uncaught
exceptions.

Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1722448

Standard: https://html.spec.whatwg.org/#runtime-script-errors

Platform coverage: all

Preference: none

DevTools bug: n/a. This is a simple function. The uncaught exception
will show up in the devtools of course.

Other browsers:
https://bugs.webkit.org/show_bug.cgi?id=228316
https://bugs.chromium.org/p/chromium/issues/detail?id=1233383

web-platform-tests: https://github.com/web-platform-tests/wpt/pull/29738

Security and Privacy: This doesn't really provide any new capabilities.

Cheers,

Tom