Pause on Exceptions in Dart web apps jumps to the wrong location

[DanTup]

Given a simple Dart web app created with dart create -t web and the code updated to:

import 'dart:html';

Future<void> main() async {
  // TODO: Remove this delay when breakpoints in startup code work
  // https://github.com/dart-lang/webdev/issues/830
  await Future.delayed(const Duration(seconds: 1));

  methodThatThrows();
  querySelector('#output')!.text = 'Your Dart app is running.';
}

void methodThatThrows() {
  throw Exception("Oops");
}

When the exception is triggered, the pause event has the wrong location (line 6, column 16):

{
    "jsonrpc": "2.0",
    "method": "streamNotify",
    "params": {
        "streamId": "Debug",
        "event": {
            "type": "Event",
            "kind": "PauseInterrupted",
            "timestamp": 1709810801870,
            "isolate": {
                "type": "@Isolate",
                "id": "1",
                "number": "1",
                "name": "main()",
                "isSystemIsolate": false,
                "isolateGroupId": ""
            },
            "topFrame": {
                "type": "Frame",
                "index": 21,
                "code": {
                    "type": "@Code",
                    "id": "3",
                    "name": "main$",
                    "kind": "Dart"
                },
                "location": {
                    "type": "SourceLocation",
                    "script": {
                        "type": "@Script",
                        "id": "2",
                        "uri": "org-dartlang-app:///web/main.dart"
                    },
                    "tokenPos": 1339,
                    "line": 6,
                    "column": 16
                },
                "kind": "AsyncCausal"
            }
        }
    }
}