[GR-74746] Arrays representation in debugger

[marat-gainullin]

Describe GraalVM and your environment :

• GraalVM version: 25.0.2
• JDK version: open-jdk25
• OS and OS Version: 24.04.2-Ubuntu
• Architecture: amd64
• The output of java -Xinternalversion:

OpenJDK 64-Bit Server VM (21.0.10+7-Ubuntu-124.04) for linux-amd64 JRE (21.0.10+7-Ubuntu-124.04), built on 2026-01-22T23:46:23Z by "buildd" with gcc 13.3.0

Have you verified this issue still happens when using the latest snapshot?
Yes

Describe the issue
Neither VSCode debugger, nor Chrome Dev Tools show the contents of an array while debugging.

Code snippet or code repository that reproduces the issue

    @Test
    public void inspectorScriptTest() throws IOException {
        try (var context = Context
                .newBuilder(JS)
                .allowIO(IOAccess.ALL)
                .option("inspect", "8787")
                .option("inspect.Suspend", "true")
                .build()
        ) {
            context.eval(Source
                    .newBuilder(JS, """
                        const a = [34, 67, 879, true, 12, 'true']
                        f1()
                        """, "array-inspect")
                    .build()
            );
        }
    }

Steps to reproduce the issue
Please include both build steps as well as run steps

1. Launch the above JUnit test.
2. Connect to the script program with VSCode debugger, using the following configuration in launch.json:

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "GraalJS-Application",
      "type": "node",
      "request": "attach",
      "address": "localhost",
      "port": 8787,
      "showAsyncStacks": true
    }
  ]
}

3. Examine the contents of a variable in the variables view

Expected behavior
The contents of the array should be shown including the length and __proto__ properties

Additional context

Details

The Chrome Dev Tools show the contents of the array, but without length property.