[navtree] Only a single nameSpan listed for multiple declarations of interface

TypeScript Version: 3.7.2

Search Terms:

• navtree
• tsserver

Code
For the TypeScript:

interface IFoo2 {
    foo: any;
}

interface IFoo2 {
    foo2: any;
}

1. Run a navTree request

Bug:
Two spans for IFoo2 are returned but there is only a single nameSpan

{
    "text": "<global>",
    "kind": "script",
    "kindModifiers": "",
    "spans": [
        {
            "start": {
                "line": 1,
                "offset": 1
            },
            "end": {
                "line": 8,
                "offset": 2
            }
        }
    ],
    "childItems": [
        {
            "text": "IFoo2",
            "kind": "interface",
            "kindModifiers": "",
            "spans": [
                {
                    "start": {
                        "line": 1,
                        "offset": 1
                    },
                    "end": {
                        "line": 3,
                        "offset": 2
                    }
                },
                {
                    "start": {
                        "line": 5,
                        "offset": 1
                    },
                    "end": {
                        "line": 7,
                        "offset": 2
                    }
                }
            ],
            "nameSpan": {
                "start": {
                    "line": 1,
                    "offset": 11
                },
                "end": {
                    "line": 1,
                    "offset": 16
                }
            },
            ...
        }
    ]
}

For VS Code's tooling, we'd like to have a list of all namespans

Start by reproducing the issue with the TypeScript 3.7.2 navTree request using the two merged IFoo2 declarations shown in the report. Trace the navTree response generation and update it so each declaration's nameSpan is represented; done means the response contains both name spans and the existing spans remain correct.